Should I keep on with my drum lessons?

I have been learning drums for three years now and I am curious to whether I should stop. I have been trying to do my grade 3 but I am not enjoying it and have been putting of practise. I am a lazy student when it comes to drums, but now I don't feel like I am having fun. To be honest, I avoid practise. I just feel a bit rubbish at it. I don't think I am good enough to perform. My drum teacher insists that I am good at it but he has to, right? Also, I wanted to take music GCSE and sadly I had a lesson clash, so now I am going to do drama. :-( Maybe I am just lacking confidence and practise, but I'd rather be doing singing lessons. I feel guilty for wanting to drop drums because it seems like a big waste of time and my parents money. And because I feel as though I am letting my teacher down.

Is it worth me carrying on? Or should I move onto singing lessons? (If I got on the music GCSE course I would have been able to do both, the school would pay for my drum lessons.) I liked being a drummer but I don't know what to do. AAAAAAAAAAAAAAHHHHHHHH.