I have no libido

I’ve been diagnosed with endometriosis this year and been suffering for a few years with it. I had an op but only got a month or so relief. Sex has hurt in the past and I’ve felt sick a lot. Sex is the last thing on my

Mind but not the case for my husband who thinks I’m no longer attracted to him. It kills me to turn him down so often but I can’t force myself, it’s just not right. Last night he tried for a good hour (rubbing me, cuddling into me) , I’d had a migraine all day and just wanted to sleep. I don’t know what to do anymore, I actually don’t want sex ever, it’s ruining my marriage. I’m really scared he will get sick of it all and leave.