Super skinny boyfriend comments on my weight ALL THE TIME

This is long and kind of a personal rant- sorry in advance! But I'd appreciate some advice!!
I am 130-135 and 5'4. My lowest weight was 115 (and I was chubby then) before freshman year of college and I guess my highest is right now. I have a small body frame so I have like 30 extra pounds of fat!
The other day my boyfriend, who is not more than 120 pounds when he's got a heavy winter coat on, tried to get me to give him my new(ish) shorts that I was wearing by saying "You should let me wear those. They look too tight on you." They're baggy/sporty shorts and when I SHOWED him there was like a good 5 inches of elastic left he said "Oh wow." As in oh, wow, I thought there was no way you could fit into those but hey, what a surprise. like "wow, those must be some really magically stretchy pants to accommodate your enormous butt." I know I'm not misconstruing it because we've been together for YEARS and know what his tones mean by now. He often says stuff like "I can't believe you managed to squeeze into those jeans" or "how do you DO it?" <- when referring to how I managed to get a big butt b/c he has no butt at all.
He's like skeletal skinny because he has diabetes and I don't think the calories get absorbed and he is also active. He eats loads of foods and never gains a pound. He spent last week at my place and literally- over the course of the week he was at my place (I pay for my own food and rent, etc) he ate 6 entire boxes of the cereal I had (1 box was the family grande size). When there was no food left, he left. lol...
Also this weekend there was hardly any food in my place (because he ate it all) so I searched around and finally found some pasta and cooked it while he watched TV. He then said we should share it and while I was cleaning up the kitchen he ate almost all of it. I said "y'know I really want some spaghetti." He let me have most of what was left but in a sort of favor kind of way.
Then the next day while we were out he said "What's up with you these days? You used to just eat an apple a day. Now you're eating all the time." this stuff is really triggering- it either makes me want to fast all day, or sometimes it makes me binge for some reason- because it sounds like he's saying I should go back to eating nothing at all and I guess a part of me rebels and yells internally "HEY I buy my OWN food I should be able to eat if I want to!!"
So here's thing: before I met him I was a pretty healthy eater (after a childhood of candy bars and doritos I'd made a lifestyle change) and weighed 115 after a summer of exercising and eating right. Then we met and we would eat junk food together. he gave me my first piece of candy after a 5 month sugar hiatus.... lol. I gained maybe 10 pounds quickly (this was also freshman year of college so lots of changes and whatnot). To lose it I started copied his eating patterns. He used to not eat all day until 6pm or so and then he'd just eat 1000's of calories at once - mainly by going to relatives houses and eating everything in their cupboards b/c he never has a job or money. So I would fast all day and then try to eat only an apple when I got home. Which actually worked, weight wise, but I felt weak and loopy all the time! I used my college meal plan to feed HIM because he had no money, and I would eat junk food because it was cheap when I couldn't fast any longer. Then a year later we lived together and again he never wanted to buy the food yet wanted to eat it. Whenever I bought food he ate it all (this didn't happen just once, like on a regular basis) so I at first I didn't eat all day and made up for it by having a bag of candy at night to get my calories in, and tried not to buy food to save money. but then I got into the habit of binge eating whatever I could buy on the way to school. So that I wouldn't be hungry yet wouldn't be spending loads of money on food that he ended up eating! The food I bought tended to be high calorie sugary junk food, and I became an emotional eater on days when I didn't want to go back to the house, we were have relationship problems that year I think. Next year of college, I recently got my own place and started cooking healthy food, then he sort of moved in after a bad situation with his old place. Then he moved out sort of, but he shows up randomly for days/nights/weeks sometimes and the kitchen is always completely bare when he's gone. So I've gotten into the bad habit of -whenever he says he might come over- eating all the food I can eat just so he doesn't eat it! It's a really messed up situation! I mean- I know he needs the calories and I'm trying to lose weight so I don't WANT to binge and take out a few days worth of food at once- but if I don't eat it before he comes over it's always gone. And I'm on a budget so I can't afford to buy stuff that's supposed to last for a week and have it gone. I'm now in the bad habit of binging (never really purging tho because I feel like food=money and it'd be throwing it away even if I don't need the excess calories) I am a VERY money-conscious person, or I try to be.... And I'm just all messed up mentally right now b/c I know if I just ate wayyy less (like a 300 cal meal a day) I would both save money and lose weight- but I want to lose weight in a healthy way and count my calories right. But whenever i eat healthy food around him I feel self conscious because I can eat SO much of certain things and still have low calories, but he'll comment on how it looks like I'm eating alot. Or he'll just look at me all hungry-ish and i'll feel bad.

Does anyone out there have a super skinny boyfriend who seems like he can eat whatever he wants? And how do you deal with it if he makes comments about your weight? Or comments about your eating habits if you try to eat healthy? ORR if he eats all your food and never pays for anything?!