mentally exhausted interacting with other people

Yep. I do what I have to do to get through my work day, but then stop interacting as soon as I can afterwards.

I can easily switch off in a conversation and then it becomes difficult to continue without starting to feel a bit frustrated and wanting to be somewhere else. The worst for me is WhatsApp groups - I can't stay engaged for months on end having random messages / chats. I had to say to friends that I couldn't keep replying, but I don't think they understand why and it's too hard to explain.

I have the same experience with messaging.

I have the same experience with messaging.