So sorry you're being subjected to something that is so triggering for you, especially in situations where you can't get away from it.

If your clients won't turn the tv off, is there any way you can use noise-cancelling headphones? Or is there any way that you can ask your boss to give you other clients? This may be something that's covered by the Americans With Disabilities Act. If you're not in the US, your own country may have similar laws.