I am late to this post, but as someone that can relate to having to deal with pretty bad back pain while working at a restaurant, /u/throwawayssllayo, I think that your BF has a fatal misunderstanding of some blatantly obvious things.

First of all, respecting physical labor more than a desk job is ignorant at face value. If all humans did only physical labor jobs for the sake of mutual respect, we would stagnate as a species and barely progress at all. For the sake of human progress, we need higher thinking and people who practice it professionally.

Secondly, the fact that you'd make more money at a desk job than physical labor isn't your fault, and you're not in a position to change that. Him being so mad at you for that seriously indicates a hugee inferiority complex. Even if he has an argument about white collar salaries being disproportionately higher than blue collar wages, white collar families usually live comfortably while blue collar families usually struggle to make ends meet. His argument is that he wants to bring people down with him instead of arguing that blue collared workers deserve to get payed more to be able to live comfortably. That inferiority complex is also exemplified crystal clear right here:

he acknowledges that he hates his job, but refuses to look for another because he thinks he CAN'T get anything better.

He also fundamentally doesn't understand that white collared people don't make more money than him just for sitting on their asses. He literally doesn't get that, in fact, what white collared people do is fundamentally much more vital to society than what he does, and that there are wayy fewer people that can do those things. Anyone can dig a hole, or hammer nails, or put shipments on a truck just to drive it somewhere else and unload it. Not everyone can do complex math though, or have an in-depth understanding of literature, or make sense of science, etc. The ability to do those things (higher thinking) is simply much more essential than any capabilities that your boyfriend has. This is very basic and says a lot about how truly simple-minded of a nitwit you are dealing with.

I don't think you should stay with him no matter how this situation plays out. For all intents and purposes, he just demonstrated how truly conceited and selfish he is at heart. You should not stay with a person like that. I really think you should show him this post though, so that he see's how much you respect physical labor jobs. I'm sure he would be humbled by those first two paragraphs. I highly doubt he knows how much respect you have for his work and probably even assumes you look down on him for it (the way he assumes society does).