Boyfriend has no sex drive

We've been together for 3.5 years, I'm 20 and he'll be 20 in March. He has no sex drive, we'll have sex once a month if that (it used to be a lot more often, it's only dropped back in the last 6 months), he never initiates it's always me, I have a really high sex drive so it's really frustrating for me.

He's still really loving, tells me he loves me, cuddles and kisses but it never leads to sex.

It has started to cause self-esteem issues on my part because I feel like he doesn't find me attractive anymore. He's my best friend & we're almost always together and we tell each other everything. I've told him about how this frustrates me and he says he's sorry but nothing changes. Do we need counselling? Or could there be another issue?