EP, you are never going to lose an ounce if he is sitting like an albatross on your shoulder and squawking about it. Know your boundaries and don't take personal responsibility for the fact that you've got a miserable man on your hands. Especially don't let him pin it on your weight, or manipulate you into believing that your weight is the only problem. If he wasn't projecting whatever IS making him dissatisfied with his life on to your extra 2st, he'd be blaming it on something else external to himself. Fat-phobic? If he's consistently incapable of seeing through fat to the qualities that really matter, he's going to become very short of friends as the population gets chubbier.
What you do has to be your decision - grin, bear it, inwardly seethe, and shed a few tears in private, or tell him that this is how you are and although you're carrying an extra ounce or two you're getting fitter by the day, or tell him that this is how you are and he's going to have to live with it and you'd welcome a bit of appreciation for all the things you are achieving in other areas of your life. Or ask, seriously, for his support - and, in return, keep your part of the bargain and let him see how hard you are trying. As a generalisation, men can't tune in to the "food-as-comfort" thing which we women often indulge in, and certainly can't connect with the fact that your brain is switched on to a healthy lifestyle yet what he sees you doing is completely the opposite. It really scrambles the poor simple souls.
Equally, beware of projecting your own dissatisfaction with your weight on to your other half. Is he really making an issue of it, or are you prodding him into agreeing that you're too fat, then taking it personally when he DOES agree? Or could he be getting fed up with you going on and on about needing to lose weight yet always appearing to be wrapped around a chocolate biscuit? I'm not being deliberately provocative - these are all behaviour patterns I've come across frequently in couples, and if you recognise yourself there, please give the poor fellow a break!
I hope you feel a lot better in the morning. You can survive a day in college - you know what you should be doing to benefit your health - your own health, for you're the only one who has to live permanently in your body - and you've got the strength and intelligence to carry it through. And at the end of a bad day, get the man to look after the boy for an hour and go and do a run or an exercise class instead of hitting the fridge. You'll feel so much better for it. In the long term, you CAN sort these issues out.
Blessings, V-rap.