Sex....should I have it?

I want to have sex....we havent had sex in over 6 months...this is a really bad pattern we have seemed to establish over the last four years....and until I give in...because I want sex....we don't. We've been married for 35 years. My husband has become very controlling. He refuses to go to a counselor. He says its all my fault. I have been catching him lying to me alot. He's been on my computer viewing porn and tried to teel me it was my son on the site. So of course I don't trust him....I can't have sex with someone I don't trust...yet I really need and want to feel close to someone. How do I interrupt this pattern....do I leave?