Non-existent sex life

I have been with a man 13 years my senior for two and a half years. I'm 24, he is 37. I just want to make it clear that I am financially stable and pay my half of everything. I had faced sexual abuse by previous boyfriends so he always told me he would take it at my pace. It took about 6 months before I was ready and he was very patient. Now we're having sex maybe once every six months and only after I cause an argument. I've been what I thought was supportive in asking him if maybe he had problems but every time it's my fault for not doing this or that right. I have even asked if this was an issue in previous relationships and he tells me it wasn't so it feels like it's all my fault. It's completely destroyed my confidence, I am used to having partners who find me very attractive and can't keep their hands off me. My depression has come back full force and it's gotten so bad that whenever I do masturbate now (about once a month) I end up in tears thinking about how the man who I love won't be with me. I feel like I should be in the prime of my life and my career is getting there but my home life leaves me feeling worthless. Every time I try to break up with him, he promises it will change and I am too dependent on him now to let him go. I know sex isn't the be all and end all of relationships but I just wish he would be honest with me. I love him and in other ways, he is lovely. He works all hours, we have a lovely home together and next year, I will be going back to study to become a teacher. I feel like I should just accept that I will not be having sex in this relationship but I can't. I've got no one else close by that is more than a work colleague and I'm scared that my depression will spiral if I leave but I'm deeply unhappy right now.

This is sad.
A couple of months and not one reply !

Here's my take on this, based on the little information available.
- You came out of an abusive relationship and found an older man who was hugely supportive and patient, waiting a long time to have sex with you. Sounds very positive.
- Now, it appears the older man is comfortable in the current relationship but isn't interested in you, or sex, or both. Sounds unusual in a meaningful relationship.
- A very good friend of mine finally tossed her husband out when the kids found gay porn on the family computer. Could this man be gay? regardless of what he says, could he be gay?

- Time to walk away and find a new relationship that is more of "The Whole Package." Love, trust, shared interests, balanced financial partnership, common sense of humor. common friends, AND similar libido.