Hi @shulberger and welcome to Dementia Talking Point. This is a very supportive community and you'll get lots of help and advice here.
I know the thinking people on TV are interacting with you is a common feature of some people's dementia. I didn't notice it with my mum as she didn't watch TV that often due to her poor eyesight, and it's not something that she's mentioned since she's been in care. She did seem to think Gene Kelly and Donald O'Connor in
Singing in the Rain were really performing for us when we watched a bit of it on the big screen in her home, but she enjoyed it and wasn't scared. That doesn't really help your dilemma, though. I wonder if this thread
Compassionate Communication with the Memory Impaired might help. If your mum is getting upset maybe tell the people off on the TV, send them away and change the subject. Offers of tea and cake can sometimes help.
Please don't think you are being a 'bad' daughter, you are doing a brilliant job looking after your mum, and the current covid circumstances have made that so much more difficult than it was. I think you need to be chasing up a diagnosis for your mum, but also some help for yourself. I think contacting the support line on 0333 150 3456 and
dementia.connect@alzheimers.org.uk would be a good idea to talk through your options.
Now that you've found us, keep posting,