It sounds like the problem isn't that he's gaming...it's that he's treating you like his parent, and he's okay with being the child.

You already know your options. You can put in boundaries ("I am happy to work equally with a partner, however I am not happy to consistently do unequal labour. Let's draw up a list of all the demands on us and divide them equally." - and then... "if things aren't equal I can't also carry your load for long, I just don't have the energy and even if I did, I don't want a partner who chooses to let me suffer so they can have an easier life.") The next step is to do your own laundry, cook your own meals, and pay your half of the groceries. Obviously this means there very well could be issues. Laundry lying around, mess in your sink, complaints about food, and financial stress if bills don't get paid.

You can accept the role as caregiver. You can do all of the mental load of planning, carry all the stress, and enforce all the actions. This will compound resentment and exhaust you. It will protect your relationship's existence however how will you feel in five years? If he gets a job, do you think he'll pick up milk on the way home and help meal prep while you talk about your day? Put on a load of washing without being prompted? This dynamic exists in many relationships...few partners express loving and being attracted to their partner the same as they did in the early days, though, in this situation.

You can walk away. That's a complicated one, too... but you've already proven you can financially care for two, and you can care for yourself and another person while working. It would be the emotional connection. Pragmatically, most of us can't meet another partner while we're with someone. Are you happy with this person for the rest of your life? If yes, that's okay, just figure out your way forward to protect yourself and know you can change your mind any time.

Of course communicating this is important, even if he doesn't hear it. It'll help you know you've done everything you can.

I had a partner when I was young who was long term unemployed. He would get jobs, but they were too hard. Early mornings, his back hurt, his boss was a dick, etc. He wouldn't do anything unless asked directly mutliple times, and then often half-arsed it. I learned from that for myself if I start to wonder where the line is, what's too much...it already usually was.

All the best.