No sex drive

Hello:)

I’m not sure if it’s just me or what I should do but I’m starting to go crazy.

I’m 21 and my partner is 24, we’ve been together over 3 years yet our sex life is non existent.The first month of our relationship was great, everyday, maybe twice a day. Then all of a sudden it stopped. And since then I’d be lucky if we have sex once a month. I’ve tried talking about it, tried new things but he says he just isn’t that bothered about sex. If i wear nice underwear he doesn’t notice, if I try and be sexy, he doesn’t notice, nothing I do seems to work.

And when we do have sex, I have to instigate it and put in all the effort, it’s really starting to get to me. Talking doesn’t seem to make any difference.

What should I do?