There's a thread of mine floating around here somewhere about a close friend of mine (who lives with me actually) and my attempts to "help" her with her dumpster fire of finances. All it got me was thousands of dollars in back rent that I will never be paid and a good bit of resentment toward her for taking advantage of my love and kindness again and again. I made tons of excuses for her over the years as to why she couldn't get it together... lied to myself about her ability to change, lied to myself about her willingness to change, lied to myself about her manipulation of me, etc.
I gave her a pass on literally THOUSANDS of dollars in rent because, in my mind, I was helping her dig herself out of her financial hole... obviously since she wasn't paying rent she would be able to use that money to pay off debt and start saving.
Spoiler: she did NOT use that money to pay off any debt, she defaulted on her existing debts, AND she incurred more debt to the tune of $36K by buying a new truck.
We had a few heart to hearts and I offered to help her with her finances by looking over her entire situation, assessing the damage, creating a budget, and setting up an Adulting for Dummies monthly schedule for her bills/debt payments. I assumed that she just lacked knowledge and understanding and that once I provided this foolproof plan for her to improve her situation (which, by the way, still allowed her SIX HUNDRED DOLLARS A MONTH for "fun" spending), she would take this opportunity and hit the ground running to get her shit together.
Spoiler: she did not do any of that, she continued on with her terrible habits, and just this weekend she left a letter out on the counter from a collector for a NEW card that she got, maxed out, and got sent to collections since our last talk.
We are in a much better place these days, but that's only because I set boundaries FOR MYSELF. I decided that as long as she pays me rent each month then it's not my business if she files bankruptcy at 30, gets her truck repossessed, and doesn't save a dime in the process. I love her and wish she would do better for herself, but loving her doesn't mean that it's my problem to fix her. If I take stock of all the "help" I gave her over the years it sadly all amounted to nothing... in fact, her situation got worse during my help, AND it was to my own detriment (did I mention she owes me thousands of dollars?)
I am sorry you are in this situation. I can't imagine how much more difficult it is when the manipulators are your parents. I just wanted you to know that I do understand your desire to want to help them and even the multiple "wrong" decisions you've made to actually help them over the years, because I've made similar choices. But it's best to just cut your losses, admit defeat, and set your boundaries. For me, my boundary was "I will forgive your past transgressions IF you pay me rent every single month going forward. BUT if you do not do this, you will need to find a new place to live, even though we are friends." Maybe your boundary is "I will help you stop the bleeding by freezing your cards, helping you sell your house, and even subsidize your living situation while you pay off your own debts. BUT if you do not do this, I will not help you sort out any part of this mess, and you will have to work it out on your own."
Good luck! It's a shit situation.