I think maybe you "came on too strong" with the "starting over and having a life together" talk too long and too often after she had repeatedly said she wasn't interested in that at all. She's sort of decided you can't get that through your head and the only way around that is to avoid you.
Should you stay or should you go... I can't tell you...
However, if you decide to stay do so very casually and in the background. Put all this relationship, life together stuff aside for now. If you mean it let her know you're there for her if she needs support or whatever, and then put her needs before yours for awhile. And your right, you may very well be waiting for nothing.
If you walk away, don't be mad and still treat her like a friend.