Need advice. What is the right thing to do?

Hi guys I in a bit of a dilemma any advice you guys can give will be much appreciated. I’ve been friends with this girl for about a year and a half and we got together about 2 months ago. But we’ve been out before and she ended up ending things. But then New Year’s eve she wrote a letter confessing her love for me. But since we’ve been back together there just doesn’t seem to be much to our relationship social or physical I offer to take her out but she just doesn’t want to go out anywhere, which annoys me quite a bit and feels like a form of rejection. She can also be quite hurtful on valentines day I bought her an expensive necklace and she just didn’t want it completely rejected it and got in a mood because I had bought her a gift. The last 2 weeks I’ve been thinking long and hard and I’m considering ending our relationship.
But heres the dilemma this Thursday its her birthday and to break up with her before her birthday just seems so cruel and heartless but then is it wrong of me to continue the relationship under false pretences until her birthday passes. In no way is it my intentions to hurt her but what is the right thing to do?

oh wow.. If you don't love her anymore its better for you to break up with her. Its cruel and heartless only to stay with her because of her birthday..