You can't change him or his responses. You can only change how you react to him. Yes, he was rude but I also see a lot of "poor me" and passive aggressive behavior here.
If he's running circles around you, you can say "Hey, babe, if you want to run why don't you run on ahead, it's distracting to have you circling me and I'm fine on my own."
Keep your focus on your weight loss, without making excuses for why it was easy for him.
When you said "that that sort of attitude makes me want to go and eat myself into a stupor his reply was, "I don't know how to support you." " What did you want his response to be after you essentially said that he was the one making you fat because you wanted to eat yourself into a stupor. Imagine an alcoholic talking to someone and saying "your attitude makes me want to drink myself into a stupor" or someone who cuts telling their spouse "that makes me want to cut myself to shreds." Not productive behavior, and not the behavior of someone who wants to change for themselves.
If he's telling you that he doesn't know how to support you, you need to let him know how. I'm assuming that you love this man (and that he loves you) and that are planning on being with him for a while. If you are both on the same team, act like it. Tell him: "Here's how you can support me: walk with me every once in a while, tell me I'm doing well, listen to me when I talk about my struggles, call me on it when I'm being passive aggressive or using my eating as a drug or a weapon."
If I'm wrong in my assumption that you love him and he loves you, then that's an entirely different issue all together....