@Totallybannanas I’m so sorry, this all sounds sounds so hard!
even separately these things would be overwhelming and massive, but you are coping with so much at once love, no wonder you are feeling burned out and done in.
Im trying not to leap in with solutions, and this may already have been suggested/thought about, but when my mother was in a very similar situation with my gran, she found the support of a ln adult social worker and care coordinator very helpful. The care coordinator supported her to navigate the finding of a good home, and helped work out what next steps were. She made a call to adults services and explained how overwhelmed and confused she was with the process. If you are still offering lots of care to your dad there may be some options open up with an adult care assessment?
re your son, it sounds like he needs to engage in some support for his substance/alcohol use. But this will need to be when it’s right for him. As hard as it is you can’t get him back on track, and you need to have boundaries to ensure his dysregulated behaviour doesn’t become abusive toward you and your elderly mum.
mostly I’m just here to offer you a hug and tell you that feeling this way is understandable in this incredibly difficult situation.
you are precious and important, and your needs and mental health matter too.
A visit to the GP or a self referal to talking therapy may help?
the Samaritans are amazing for somewhere to talk and vent and cry, they are supportive and offer a place to let these feelings out with no judgement.
I wish you all the best x