I hope you don't mind me popping in for a moment. I've just finished reading this thread and think life has been very unfair to you and don't wonder at all when you come across as bitter.
Shelll has been giving you warm support and htat is good, makes one feel less alone.
I was struck by something Chris_Tas said about acceptance, which I don't for a moment believe was meant in a nasty way, or to belittle all the horrible things you have to keep on facing.
It's just you are doing the best you can with all the illness and unsympathetic people - plus not enough cash of course. And these are things you only have so much control of. A lot you have simply to live though a day at a time.
Acceptance is something to aim for, however to get there for me I use the idea of trying to put things to one side for a little time. That's not easy when you are in pain and discomfort (and probably hungry too) but if you mange to do it for a little while then there may be things you can enjoy. Then more acceptance may come.
Your description of that musical and the way the performers carried on after dropping something probably took your whole attention - at least for a moment. For that moment the world may have changed and you were not weighed down by all the everyday things.
So do you think it is worth seeing if you can use that sort of thing to distract you and point you towards something you might enjoy? I try to use mindfulness (just a fancy name) as a start to get me to a calm frame of mind. I'm not that good at it but find the free smartphone app Smiling Mind is excellent - though it took practice.
I know your phone is not that great but it might do
Once I'm a bit calmer and my concentration is not focused on my own ailments and pain I try to have something ready to do to keep me that way. In my case it is books or movies (get them for free from the Library) or other things.
Of course I've no idea what you might find to take your mind out of problems - maybe music as you do seem to like musicals. Could you teach yourself to play/sing something?
What ideas do you think you might like?
I hpe things get easier for you