Have I screwed this realtionship up??

Hello everybody. I have been friends with this girl for more than 2 and a half years. Then about 6 months ago I starting falling in love with her but was afraid it would ruin our friendship. But then about a month ago she tells me that she is very much in love with me and has been so for a long time! Oh sweet happyness! Yeah well...she was very afraid that it would ruin our friendship and she had alot of doubts if it could work out but I persuaded her to give the two of us a chance as a couple.

The first couple of days went great and she even introduced me to her mother as her "boyfriend"...but then this happened:

One day we were talking about her personal situation which was pretty bad at the moment (depression) and suddenly and out of nowhere she says:
"What is going to happen with the two of us when I get better again???" Being taken by surprise I responded (very stupidly): "Well...I certainly hope you are not just using me because you are feeling bad!"...I can see now that it was probably the most STUPID * * * * I have EVER said to her in all the time I have known her. The worst thing is that I KNOW she wasn´t just using me. It was a huge thing for her to admit she was in love with me and then I say some * * * * like that. I just feel like I defiled the beautiful love she had for me. I still don´t know what she meant by that question "What is going to happen..."
but at least I could have asked her: "What do you mean?" instead of blurting out that crap which I díd.

Anyways after this incident she has cut down contact considerably and doesn´t talk to me anymore like somebody who is in love. She hints about other guys and now we only talk 20 mins every other day where we talked for HOURS every day before. Do you think it is because of what I said? Has that remark made her regret being my girlfriend or made her love vanish?? I guess what I´m asking is how would a woman think of a man who said this? What would such a remark mean to a woman? And would it change her feelings?

I know I made a HUGE mistake but can it in any way be reversed? Can I make up for it again?

No, you said the right thing. That fact that she said that you were her boyfriend so quickly...that's symbolically peeing on you to say "He's mine." Posessive that quickly? And then the line, "What is going to happen with the two of us when I get better again???" That line is total drama, BS.

You hit the nail on the head with your comment. Good for you! She's just thrown off by the fact that you were manly enough to speak the truth.

I was in a situation similar to yours. I guess when a man thinks we are using him, it hurts us quite a bit. Women are very emotional and when we confess our love to a guy, we are trusting him with our heart.
We know that men are not perfect but when they accuse us of things that are not correct or true then we can become very distant. Some girls become "clingy", some become "distant". I would suggest taking her some flowers or chocolates. I know this would melt my heart if a man done that to me. It shows that you are sorry and you love her. Just because you are in a relationship, don't stop pursuing her. Maybe she thinks you don't care, show her you do.