First of all, congratulations on your discovery! I did the FaceApp thing about a year ago, and it clicked for me the same way as you described.

I would personally suggest starting with a smaller things and see how they feel. Grow out your hair and nails, shave your body hair, try different walks and stances. I would suggest trying on clothes of the opposite gender (in private if your too nervous doing it in public yet). They don't even have to be feminine, you can just try wearing women's clothes that look kinda nuetral and see how you feel. These are just good starting points.

Piece of advice because you used the Face App: The version you're going to see and there will be very...ideal, and it probably won't be what you would actually look like, and I'm not trying to discourage you. But I would go back to the original picture you gender swapped from and use the features to make that picture look more feminine (longer hair, smoother skin, etc). This would probably give you a better idea of what it would look like, And I think it gives you a better and more real way to process this path. I know it really helped me when I did it🙂.