Girlfriend is acting like she's not bothered?

So we've been together for 5 months and we had a few problems earlier on which ended up in a massive argument and we was going to split up but she decided she wanted to give things another go with me. I didn't cheat or anything before you ask.

But anyways ever since then I've done nothing but be really nice to her, I've been making loads of effort, always trying to make her happy and make it fun. I've treated her like an absolute princess and spoiled her now and then. Just doing everything I can to be a good boyfriend yet she's just acting really off with me.

She won't make effort on text, she never makes conversation, always having a go at me, acting like she just doesn't care at all. I gave her the chance to walk away form alll this and it was her choice to give me another chnace, and now that I'm doing everything she wanted me to do, it's like she's still not happy.

It's pushing me away I'm not going to lie because I just think what more have I got to do to make this girl happy? Like what is wrong with her? What more does she want? I just don't know what to do anymore?