Please help!

Please help!

I am in desparate need of help/support. I have been with my partner over 2 years and we live together.

For the last year i have been unhappy as we are not having sex very regularly at all. It could be every 4-6 weeks and it only seems to be me who instigates it. We have a talk every few weeks about it which he hates but i am so frustrated that i have to talk about it as i feel totally unattractive and i know i am not. He makes no effort to instigate sex and i sometimes think if i don't then we will never have sex again.
He says he likes having sex and that this has happened in previous relationships. He doesn't want to have sex for the sake of it as he thinks it would just be "going through the motions".He just simply does not feel like it!
It finally came to a head this week as it's now been a few weeks since we last had sex and i am at breaking point. I said to him maybe we should have a break, he said no he didn't want that, i also suggested a sex therapist and he got very angry at that and forbid me to go alone as he will not go.

I am absolutely distraught and i don't want to end my relationship as i love him and everything else in our relationship is perfect. He doesn't want to lose me and got upset yesterday and said he promised he would get it sorted.
How? I really have no clue. I always use to have so much confidence in the bedrrom, using different outfits and making it exciting. I trust him 100% and i know he is not cheating on me. We also work together so we do live out in each others pockets. Could this be the problem?
I would really appreciate some support and advise.