I fancy my friend but i don't think i am good enough for her?

OK me male and mi friend female have bin good friends for 2 years i have fancied her from I first seen her and every day I just kept liking her more and more but I fought I would ruing the friendship so I tried to ignore her to see if I wouldn't like her in that way any more any more and it worked so I started talking to her again and I feel for her all over again i think she is amazing and perfect and I don't think I am good enough for her so anyway like 2 months ago I told her I fancied this girl (it was her) and I described her in every way I could to drop the hint that I liked her but I don't think it worked so 2 week's ago we where talking on msn and she said how are U and I said bad U she said good why what's up I said its just the girl I like I don't think I am good enough for her and she said right who is this chick and I said it doesn't matter and she said it does so tell me and I said it doesn't matter and this went on for about 10 minutes and then I said OK I will tell U but first U have to tell me is there any way I could f U c k up are friendship she said no so I told her she responded like 2 minuets later with oo I wasn't expecting that but U sort a picked a bad time and I said why and she said cause i have a boy and I was like ooo so any way we are still good friends we talk a lot and all but i still don't think I am good enough for her she is just to good for me and do U think I should ask her out when her and her boy break up