Relationship help /:?

Me and this girl have gotten to know eachother for about 3 months now. Within those three months me and her got intimate hy kissing holding hold etc. After about another month of incredible happiness i thought id ask her out ,make it official. She tells me no. Thats it. For about a week or so afterwards she was in a depressed state anytime i saw her, i tried to talk to her and she says she needs space. I know for a fact it was not something i did(considering i had been making sure not to **** this relationship up,not that i ever have). Another two weeks have gone by and she still doesnt show interest in me. I cant see what went wrong because just a few weeks ago we were in mad love. This anguish she is putting me through is unbearable, and i suspect she may have found someone else, but i hate to jump to conclusions. Please help this is the girl i love and she wont take me back, i cant stand this much longer...