Anybody else fear that if they try to change their ways that they will become a different person and scared that you won't like it?

Basically a fear of the future, commitment and change. I have memory problems (self diagnosed) because I can't remember a lot that has happened to me from my past or even the day before sometimes. I was thinking it was my weed smoking but idk. 

But anyway, I am afraid that I won't be the same person or hate the person I will become. I also am scared to death that I can't keep commiting to this change. Saying that, I don't think I will remember why I stayed in the first place.

Sorry if all over the place. I'm just bad at explaining my problems because I really can't figure it out.