Another thought -- what are your resources? And what is your willingness at this time? Then perhaps people can help give you more "doable" suggestions that match your "budget."
- Your practical resource budget. (time, money, access to things like Internet, etc)
- Your emotional budget.
- Your mental budget.
- You spiritual budget.
Suggesting getting a professional counseling is a good suggestion. But it's "actual doability" for you right now may or may not be a runner if you are broke have no method to pay for it. YKWIM?
To be better able to suggest things to help you sort yourself out, maybe you could list what you have to hand then?
In terms of what you are willing to do or willing to consider.
In terms of what you are able to afford to do.
But again... nobody can give you helpful suggestions for HOW to get to your goal if your goal does not change. A goal of "Fix the unfixable dynamic in a live-in triad situation" isn't going to work.
You cannot force your poly peeps to behave in ways you want. They control their behavior. You control yours.
You may not be ready to give up the "triad" bit just yet.
So could focus on changing the "live-in" bit to see if that alleviates some of the problems of the triad -- living too close together in too cramped quarters can't help this situation..