I'm having the same issue/phase as you.
I'm 24 and transitioned very young. This was right before social media started to get popular so thankfully I have no pictures/profile of myself dressed as a male floating around the internet. Although, if my name is searched carefully you can find out I'm trans due to me outing myself when dating before. Now, I have to change my name again, which I don't mind.
Tips:
1). Cut off everyone. I mean everyone! Except your very close family. Girlfriends (especially other trans) are so catty. They will be quick to say backhanded things to your future spouse like "I'm so happy you accept her for being her" and out you. They might out you by accident or just plain association as well. It sucks but it's worth it. It's hard because making new friends and a new "past" is hard, lonely and takes times but worth it.
*** ONE BIG THING*** I stress this to everyone. Now days, it is not possible to be 100% stealth. (Unless you move to the Amazon jungle) I don't care how pretty a girl is there is always something that can give us away when closely examined and looked it. Now you can play stealth in public but when you start spending alot of time with people, it gives them more of a chance to notice these little things. Especially if you are to marry a man, he will find out eventually. You are eating,breathing and sleeping with this person. He will see everything. But in the beggining of the relationship he probably wont know but you will have to break the news to him some day (usually months in, 6 months?. I say when you both truly love eachother) by this time if he truly loves you he will most likely stay. But again there is no way to be 100% stealth. Social media, the increasing transgender awareness on TV, Social Media and Trans Education now have everyone knowing about us and our procedures.
In a way this transgender attention/awarness is bad for the girls who want to be stealth. Guys know that adams apples can be shaved, vaginas can be made even nicer than a females and lots of them have been in contact with trans and know that they can legally change their name and gender marker. Back in the 70's and 80's it was unthinkable for trans to have a vagina, unless it was a butchered mess (in a males mind). Now days they seen porn or pictures and see that surgeries can completely feminize someone. Heck, guys even spook cisgender girls that are "too pretty" have "too much surgery" or are tall and say their "->-bleeped-<-s" when shes actually not!
This is the new "stealth". I'd say you can be 90% stealth as long as you have
1.a good back story. I changed the high school I went to. I say I was born in another town. You can run into someone (happened to me in college) who went to same high school. He told me he didn't remember me in school but in my head I was like "yup you do, I was the feminine boy that hanged out with your girlfriend at the time". Ever since then I changed my whole back story. Diff town, school, etc.
2.passable (not saying pretty. Passable is both pretty and ugly. Sometimes being over-surged is what spooks people. Sometimes looking like a 4 out of 10 is more passable. My friend isn't that pretty and she says it herself but theres one thing she is and thats super passable. She says "Im passable. I just look like an ugly girl" haha. its true I give it to her).
3. nothing lingering in the past. No pictures, yearbooks, online profiles photos etc. Everyone googles people now.
4. distancing yourself from people who know your past. You cant trust anyone but yourself. its the truth. Friends fight all the time. Do you want to risk a friend spilling your tea when she gets mad? Even if she hasnt yet you never know. Plus lots of times they spill it with no malice. For example. my cousin all the times shows pictures of me to guys saying "she is so pretty. she a ->-bleeped-<- but she gorgeous right?" The other day she showed a guy a picture I sent her of my vagina (the results) and she called me and he said "yooo I can't beleive it, it looks like a pussy ur doctor did a good job". Now by now I stop correcting her cause she always did this and I know it's not done with malicious intent but still.
5. **Controversial** what I am about to say but whatever. I pretend to have this stance where I don't believe in homosexuality, transgender etc. I say it's immoral and not God's plan. I act like I don't accept them but I always say "I don't hate them I just dont agree with their lifestyle. Im a catholic girl" I don't trash talk or anything but I always let it be known that I'm against that lifestyle. But im not out there with picket signs and constantly talking about it cause then it just makes you more suspicious.
6. Stop the translingo (big problem for me) words such as "werk" "spill tea" etc will "spook" you.
7. Don't overshare and keep as many things you can private but not in a wierd way that will draw more attention but more in a way a professional at work would.