Is it normal that i wish constantly that i was this other girl?

im normally an ambitous girl, confident and sociable but, my boyfirned and i split up in feb, i was heartbroken and he'd left me for someone else but he turned up at my door a month later with flowers, and a love letter and in tears andd a few weeks later we got back together (i didn't give in easy). He finihsed me for this other girl but now i dont even associate the girl and the boyfriend together and that though dosnt bother me, but i wish i was this girl so badly, shes beautifull and rich and always looks so happy and full of personality and theres not even a celeb id rather be, i often find myself wishing i was her and it getting a bit weird where im actually feeling depressed that im not her... its not the fact that he left me for her i dont think about that anymore and im over that... i just still wish i was her, since i started thinking this i have found nothing to say to people about myself, cant look in the mirror and be thankfull of what i see even though im an average person thats not disgusting, i keep finding thing i hate myself, this isnt normalll and i no youll all click the no its not button but i just wondered if anyone was in the same boat or if anyone had advice?