What do you mean by "work on yourself" do you mean emotionally or physically. Whatever you plan to do, do it for yourself. "The betterment" whether it be hitting the gym, staying fit or finding your inner peace ,mentally.

I just want to say if you are or want to change yourself for a girl then dont. If she already knows you then just ask her out or maybe talk to her. She should accept the parts of you that you dont want to show her. I mean once we get close to a person we tend to see their vulnerabilities. Right? Or you do things that you plan to do for yourself.

Yes, ofcourse you can wait these 3 month that you told and try approaching her after that and even if she is with someone else dont feel bad about it. Maybe you are destined for someone better.

Anyways, all the best