Oh dear........on the face of it he doesn't sound very supportive BUT I bet he's worried about his mum and (wrongly) taking it out on you. I've been doing this plan for 9 weeks now and my OH told me yesterday that we have been invited out for a chinese tomorrow night for his employees birthday! I think I'm just going to have to make an excuse to not go, which is such a shame as we have avoided doing that so far and been out for a couple of other things and had SS+ food, but unfortunately I can't think of anything I could have on this occasion!
If it's just a 'nibbles' thing and not a full on meal, couldn't you 'pretend' to have something?! I don't know if thats good advice but practically I think thats what I would do if I had no other option-just to keep the peace!
Re your OH; I would talk to him. Tell him that you want to be there for him and you understand that he is worried about his mother, but that you are taking this weight loss step for you. To feel better about yourself. Tell him that you are so motivated at the moment and are so determined to do this.
I bet you 100% that his cross words to you are nothing to do with you and the cambridge diet.
Just talk to him.