I had a very very similar situation when living with my mother.
My younger brother who smokes cannabis most of the day and dropped out of college is given the luxury of doing nothing, and I mean nothing. When asked to the dishwasher, he would take 4 hours to do it, and then when he DID do it, the job was done so poorly, that there was no point. Same when he asked to make dinner, there would be times when asked at 1pm, dinner would not be served until 11pm!
I have severe health problems, suffer from extreme arthritis in my feet, and get breathless due to a combination of panic attacks and the medication I am on. Despite this, I would be expected to climb ladders, bend down and scrub the floor etc.
At that time, I did not mind contributing to the housework. What I DID mind however, was my actual or percieved lack of assistance being used as a measure of how I was a bad son; and whenever I did fail to jump the bar, (which was often) this was then used as a pretext to issue a laundry list of grievances that were bottled up and which had no relation to the issue at hand. I would not expect a person who is illiterate to give a reading of the Bible, or at the very least, to the same quality/standard a person who was literate.
The point I am trying to make here is fairness, transparency and proportionality. If housework becomes a system of scoring points and settling grudges, then that this a toxic relationship. OP, I was very fortunate to move into a bedsit, and I am financially solvent; I am unemployed and on benefits, but I am very comfortable, as I budget. Before anyone thinks me too fortunate however, temper this with the fact that I get all these benefits due to very poor health and substantial functional impairment and disability.
OP;
I genuinely feel for you, as I understand some of the dynamics and dysfunctional behaviours and the impact that they can have upon your mental well-being. With that in mind, should you require additional support, with regards to taking the next step forward and moving out, please PM me and I will be happy to support you further. Take care.