For me it took a blind leap of faith to jump into it, but I really had to look into myself first. Sounds exactly like what you are doing.
You and you alone will know what you want and what you need to do. Professionals are there to guide you but won't push you to something you aren't ready for. I, too, realized this.
Understand that even cis women have their own issues. My wife constantly thinks she's ugly and fat. She's beautiful and I told her I'd gladly trade my life for hers, many times over. She rolls her eyes. But I know women who really don't look all that feminine but there is no doubt in their mind that they are women. But if you carry yourself like a woman and believe that you are, then you are!
Beauty takes work. Yes, some people have it naturally but if you want to look good you have to work at it. Thankfully there are TONS of resources and things like clothes and makeup can make all the difference. Even personal grooming and styling can help immensely. So don't think you will be stuck as a shaven ape in a dress. If you've been looking around here then you should realize that many of us started out as manly looking men, and ended up as beautiful women. I am at that starting point and it is only when I realized what could be done then I was happy to jump right in. But even so, I couldn't live as a man anymore because it didn't feel right or authentic. I mean, my friends are growing their beards for no shave November... I think that is just gross. I mean beards are icky, they get food caught up in them and all other stuff...eewwww. I had liked to be clean shaven even though I have let myself go in the past. And now that I shave my body hair and arms and legs, it feels right. Eventually electrolysis and HRT will take care of a lot of stuff but right now I'm enjoying feeling right... and to me that is the biggest thing, FEELING right about yourself. To heck with what other people think!
You also mentioned that you are questioning why you are this way. Nobody really knows but there are theories. Everything from hormonal activity in the womb, to mild intersexed conditions, to abuse of DES and other stuff by the medical establishment. I mean who knows. But you know you have those feelings, so you have to deal with them, and only you can decide how. For some people this means full transition but for others it may mean cross dressing once in a while, low dose HRT or simple self acceptance. In the end you can try any of those things and more and get a feel for what you like.
In any case a good therapist is a must. That said, I have had two. The first one gave me some good practical advice but I felt she really wasn't doing much. The new one I have is very understanding and knowledgeable so I think I'll stick with her for a while. I do go dressed up because I feel more comfortable as me expressing my feelings to her, but it also gives me the opportunity to test the waters going out as a woman. I can't go full time yet due to work but I feel it will be soon.
In any case best of luck, I hope you find your place and your peace.