Hi Shark. You are NOT a pain. You are having a hard time.
I'm sorry this is still so difficult for you. I was trying to think of something to say to you other than, it stinks, it's hard, and I'm sorry, but that is a start.
I did have a thought; I think, if I remember correctly, that your mother was in hospital for a LONG time (months, right?) and that you visited her in hospital something like twice a day, every day. I'm sorry if I got that wrong.
So I was thinking, you've been used to visiting her every day for a really long time, in a really stressful situation. Maybe you need to give not just your mum time to adjust, but also you time to adjust, to it being a new situation, and not an emergency. (I think a long hospital stay still feels "urgent" in a medical way if that makes sense.)
I also think the suggestions here to ask the staff for information are good. Maybe it would help you if you rang the care home at regular intervals to get an update. I know I was shocked to hear that my mother was not only not upset, but participating in activities and NOT sitting alone in her room, which was what I had been imagining. Six weeks in, my mother is hardly ever alone in her room except when she's sleeping. This is a huge difference to when she was living on her own, pre-hospital and pre-care home, where she would go for days without seeing anyone (mind you, it's not what she would tell you was happening, but it's the truth).
I'm not saying your mum is going to magically turn into a social butterfly, but I do think it's unlikely she is spending 24 hours a day, alone in her room, crying. You have to remember that she is not alone, there is staff there 24 hours a day as well as the other residents. She is safe, she is being cared for, she is getting regular meals, she's getting her medications on time and at the proper dosage. All of that is good.
But the reason I suggested speaking to the staff for regular updates is that you're used to be on a "schedule" of visits with your mother, and now you're not doing that, so of course your routine feels upset, in addition to everything else that is going on. So updates from the care home could be part of your new routine, and would give you information, even if they don't immediately make you feel better.
Hang in there and try to be kind to yourself. Thinking of you.