Dog anxiety through the roof for no apparent reason

This is just a rant.

We've had our dog for three years now, he was an adult rescue. I know he has separation anxiety and weather related anxiety.

I don't know what is going on with him today but his anxiety levels are horrible today. I haven't left the house since Sunday, it's autumn so there are no storms, I've given him some calming stuff but he will not stop.

He keeps running from room to room with his ears back and tail down in a panic. Then I went to go work from the couch to comfort him but he wants to be on top of me (and he's 25kgs). I let him be as on top of me as possible but then he gets hot and starts panting. Then I move him but he keeps clawing me to get back close to me so I sit with my arm over his head. Then he keeps adjusting his head every two seconds and almost pushes my laptop off my lap every time. Now I can't get him to eat dinner because he's too anxious. For what, I don't know.

Hopefully he gets over it tomorrow.