"months and months of convincing her I really care about her"
there's your first problem. girls aren't stupid, we know you don't really care about us and are just trying to get some ass. so shes probably well aware of your intentions but being difficult playing around with you as a toy. which, she isn't in the wrong and

her.. because essentially.. that's what you're doing as well. only difference is, you think she doesnt know. but she mostly like knows. youre the fool in this situation.
why not just be upfront about it?..... females like honestly, doesn't have to be brutal like "i dont wanna date you, lets fukk" but let her know casually in passing? instead of misleading her and wasting both of your time.