The first thing to remember is that this guy is your partner, not your employee. So the only arrangement that needs to apply is one that suits you both.
As the present set-up is upsetting you, it is not acceptable in the long run, so it has to change. The only person who can initiate the change is you.
Get you partner to speak to a disablement adviser who can suggest suitable employment.
Around the home, draw up a rota for chores. Start this off by listing down all the chores, with who is currently doing them. Let him pick enough of the chores until there is an equal number of yours and his names. DO NOT in any circumstances then start doing "his" chores, even if this means going without a meal if he is supposed to shop and cook . Initially there will be some resistance as you are moving him well out of his "comfort zone"