A lot of men don't realize how all-encompassing and consuming the weight-loss/healthy living mindset can be for us. If you sat him down and explained that you are trying not to go back to an unhappily high weight I'm sure he would understand. Food pushing can be irritating, but it also means he thinks you look great and should be able to eat whatever you want!
As for the comment, it's overreacting a bit to claim he's a jerk or is autistic for commenting on someone's size. And it takes forever and a day to catch up mentally and really believe that yes, YOU are much smaller than you used to be. It takes time to adjust, but you will. Have a little faith in yourself - it sounds like once you overcome these hurdles, you'll be really happy with your guy!