I'm so deeply unhappy with my situation

Hey y'all. Im currently living in a hotel room with my sister, nephew, and cat. I was planning on moving into a place with my best friend at the end of January but that fell through. I let my sister and nephew come live with me in a previous apartment a couple of years ago because they were homeless and she let him cause a ton of damage that I was charged over $1000 for. I couldn't pay it so it went to collections and I got denied at 2 different apartment complexes this time around because of it. My sister can't pay it because she refuses to get a decent paying job.

I figured my best bet was to find a place being rented by the owner and before I found one I asked my friend if she was okay with living in an area about 20-30 mins from her job and she said she was. So I found a nice place being rented by a nice lady, sent my friend the address, the link to the listing and all of the fine details like when I was going to tour, what time and all. Only for her to say at the last minute after asking me how the tour went that she doesn't want to live in that area. Two days before I had to move out. She lives with her parents so she didn't have a time crunch or anything but she knew I did. I spent 13 hours moving my stuff into storage alone and had to use the last of my moving funds to get a hotel room.

So I texted my sister and asked if I could come stay with her (I'd pay half of course) only for my sister to tell me she lost her bs job and is sleeping in her car again. I felt awful that my nephew was in that situation again so I invited them to come stay in the hotel with me. I originally had the intention to get a room with two beds but it cost like $200 more and I can't afford it and she's not contributing financially because she's just doing a little online survey thing for money for food. So I'm sleeping on the floor.

I'm having the same issues i was when they lived with me before, she's not really parenting her son much. He peed the bed like two days ago and she still hasn't changed the sheets. It smells like piss in here and she lets him stomp around and make a ton of noise. I've told him to walk more lightly because it's rude to the people in the room below us but I gave up because she's not trying to reinforce it at all. There are crumbs and hardened clumps of food all over the counter, table, and floor. I had to tell my nephew to stop dropping food on the floor because my cat will eat it and I've seen her almost throwing up twice now in two days. My sister only says something after I do.

I was recently diagnosed with anxiety and adhd and all of this is making it worse. I've been crying at work, last year was really hard for me like I've been unintentionally distancing myself from my friends and not doing anything besides throwing myself into work. I was hoping to try to reconnect and start going out more but I feel like I'm frozen in place. I think I'm slipping into depression, everything feels so dull and hopeless. Music has always been an escape for me but even music has been sounding and feeling dull. I'm pushing back my online therapy sessions because they're here in the room with me and I don't want to talk about this stuff in front of them and whenever I think about just leaving the room for anything other than work I feel glued in place. I want to get an apartment before the end of the month but im draining my bank account every week just to stay in this hotel. I feel so down and im disgusted with myself because I can't bring myself to even look at or talk to my sister.

It's like I want to help them but I don't have the financial means and she's not doing anything to help her own situation. She's talking about wanting to homeschool my nephew and work from home and it's like she refuses to even entertain the option of doing anything but that. I just want to scream at her that she just doesn't have that option, she needs to put him in school she can get an actual job and get them their own place.

My dad has sent me some money to help but he's in a tight money situation right now. He wants me to let them live with me when I find a place just so they're not on the street but I refuse to put myself through that again. I feel like a terrible person but not having a place where I can just be alone actually makes me want to hurt myself, this whole situation does. Even just the sound of my nephew playing with his toys feels like I'm being beaten over the head. I think something is seriously wrong with me but I can't bring myself to kick them out on the street again.

And I just found out I may get laid off from my job in a few months. I just don't know what to do and I feel horrible. Every year I think "next year will be better" and I'm always proven wrong. Things are just getting worse and worse. I know im externalizing my frustration by being so angry at my sister (and the world in general) but I don't know how to stop. Im literally pulling my hair out from the stress. Everything just feels so bleak and hopeless.

Does anybody have any suggestions or advice? How do I cope with all of this? I tried to post this on the vent sub but it got removed because I have no karma on this throwaway account.