Relationship issues, What should i do?

So I just got engaged a month ago on my birthday. We been together about 7 years, since high school on and off. We're in our 20s. We've always had problems, but manage to eventually work through it. We got into an argument earlier, because I didn't really wanna go to the gym, but I was going anyway. He is very harsh with his words and doesn't care what comes out of his mouth a lot of the time, I didn't like what he was saying so I was like let me out the car (we were still in front if the house). Anyways, he ended up coming back in the house saying things like he doesn't want to be with someone who's gonna sit on their butt all day not doing anything. I work a full time job, a very physical job, I'm always exhausted, tired, in pain, I do things around the house..Hes always on his Xbox. But anyways, he thinks I'm gonna get fat and he says he's not happy with how I look, and the fact that I don't work out everyday. I'm 5 1, around 140 lbs, for the past maybe 4 years or so. I'm not fat in any way. But pretty much he doesn't want to be with me if I don't lose weight is what he's saying. And I'm thinking that were engaged right now, if we get married its for better or worse. Not just for better. I don't want to be with him if I need to be skinnier to make him happy. Any thoughts? Thanks in advance....