It is always your choice. It is your life, your body, your decisions! You might not be ready or you may never really want to do anything that involves transitioning. I don't know how long you have known you are transgender but ultimately the choice is yours. I agree with the first response that perhaps starting on your weight and habits around that could help! I know acne is awful, it is not always eliminated through diet but it certainly can be helped! Trying to develop better diet AND eating habits could really help you out overall if you can manage that. There are many gorgeous transgender women of color and with modern tech, results can be even better than you expect,so don't decide you can't transition because of your body. You are 19,you are young and could have a long life ahead of you. I would recommend working on stuff like: health,school and yourself, regardless of your gender. BE A PERSON YOU CAN LIKE.
If you have any interest whatsoever, BUY THIS BOOK: The Power of Habit
I majored in pyschology and this book is great for anyone to read and be inspired by. It's tangentially related to your post but if you are wanting to be happier, healthier and understand a little more about the human mind and how to get yourself focused it is extremely useful. So much that I would send you my copy if you can't afford to buy it yourself. Seriously. Let me know,Ican always buy another one.
What that is is your own definition, but for example: I am FTM but i do not wear a binder when i am not at my workplace. It hurts and I wear it all 12 hours at work for three days a week and I do not want to wear it the rest of the week. So I am pretty much expecting people that are not my immediate household to still call me female pronouns. It sucks a little but I prefer it to not breathing deeply and having an ache in my back every night. I AM saving up for top surgery though, so that is the thing that gets me through hard days. I know it won't cure my disphoria, but mine is not as bad as many other transfolk and I am ok with it most of the time.
I have many hobbies, I love art,reading, taxidermy, playing games online, gardening, games with my friends and housemates, cooking and TOO MANY MORE! Find the things that fascinate you, whether they are for 'MEN' or 'WOMEN' !! WHO CARES?? If you like it , it is cool in my book! I have cis-male friends who knit and cis-female friends who LOVE SPORTS. It doesn't matter as long as you are passionate about it! I am not saying let your hobbies distract you from being trans, but it can help you to take an hour or so to get really absorbed in something awesome that doesn't make you feel like you are having to prove your gender to anyone!
STUDY/BE SMART/GO TO SCHOOL/VOLUNTEER! School can seem like a LOT of BS, and to be fair, sometimes it is! BUT you still have to work to get through a class and earn a good grade- thyat is why people with honors, diplomas and stuff tend to get better jobs. I work at a hospital, did not specialize in anything medical in college but I have experience working with autoclaves and was lucky they needed someone to do that kind of work. I went through a long convoluted chain from volunteering at cat and dog shelters, to working at a vet (which did surgery and used small autoclaves) and then at a really fancy piercing/tattoo shop that needed an autoclave worker to clean, maintain and run all their tools and machines. THAT ended up getting me my current job, which I love! I am able to save money and do a really excellent service. I am 30 and just now starting to really transition. You really shouldn't give up completely on the idea, but again,it's your life and your choice! You may change your mind someday, maybe not! It doesn't matter to me as long as you can cope/be happy and do your best!
As for Health, just try to be active doing something you like! I walk EVERYwhere. I live in a small town and I walk to the grocery store, the bank, pretty much anywhere I can. I know not everyone lives someplace that is as conducive to this kind of thing, but do what you can. If you can, try to shift your eating habits to things that are less processed,have less salt and sugar. This is HARD, but if you have time and a little spare money, you can often find things for reasonable prices that are good for you. Some of the fancier co-op grocery stores by me will GIVE AWAY food for free if it's nearly at the expiration date. Research your area, see if anyone does this by you. You can find all kinds of cool, wierd new foods AND teach yourself how to cook them. The internet has a recipie for everything! Cooking can be a bit tough if you don't do it yourself but if you are willing to put in some time and frustration it is overall cheaper and healthier for you than pretty much anything else. I honestly just love steaming broccolli for a few minutes to soften it and slapping butter or cheese on it. I know that doesn't sound all that healthy or great to some people, but it's way healthier than a burger or fries by about a million XD You do not even have to cut sweets and stuff out completely, just try to reduce them a little bit every day. Monitor your eating habits- THIS HELPS SO MUCH! Basically keep a small journal or if you have a phone with a not system and write down EVERYTHING you eat for a couple weeks. You will often realize that you and maybe even your friends eat all kinds of stuff you don't even think about. When you pay attention to what you eat, why you are eating it and when you are eating it can help you start to change. Also, if you can, use smaller plates or bowls. There's a really good study that showed if you eat less food in a smaller container or off a smaller plate,you will feel just as full as a large amount of food off a large plate. Your eyes and brain see a full plate, no matter how big it is.
Honestly, you are so young to rule out any options. If you are willing to start now and try to change yourself for the better, you can train yourself into good habits and who knows what you will want in five years, or ten? AND BY CHANGE I AM NOT EVEN TALKING TRANSITIONING, but that is also still something you could choose if you wanted! You should not feel pressured to do anything you don't want to do, but I urge you to explore the reasons you are afraid and see if you can think of solutions to the problems you might expect to come up. If you have access, try reading books you might not otherwise on subjects that interest you. Read about philosophy and psychology. I recommend learning about Cognitive Behavioral Therapy it is extremely useful and interesting without being too boring for most people.
Don't let anyone bully or force you into a choice, one way or another. Being a teen sucks and is hard for everyone, trans, cis, color, white, all teens have a rough time. I did not even know Iwas trans until about 25 or so and while that did explain some of my teen angst, things are changing for you in all fronts of you life/body/world so take some time to just think on what you like, who you are and what some goals you might want to set for yourself.
If you have a counselor at school you can trust, can you talk to them? You don't have to come out,but maybe see if they can help you by talking about other issues? I went to a therapist for gender issues and she ended up seeing me long term for anxiety. It wasn't even something I really thought was a problem until she asked me if I always felt stressed. For me, the gender issues are almost always secondary to me being a bit of a spaz that worries about everything.
I hope this isn't too much nonsense, I've done a lot of life changing that isn't at all related to my gender but it has really helped me feel better and more whole a person, regardless of what the grocery clerk calls me!