Thank you so much.
We're back from the vet. He didn't find anything severe except he has a lot of worms and some constipation (yes, again) the shaking or spasm could be due to the constipation. He told me to wait with the deworming medicine and that might help him go poop if not he'll be on lactulose. The little guy is so dirty he needs a bath, but not today, too soon, too much stress.
The kitten's about 3 or 3 and a half months.
He just ate again. I'm giving him small meals to prevent any reaction I don't know when was the last time he ate so better safe than sorry.
I'll keep focusing on the positive and we'll get through this, the cow and me and then his furever home.
I'll keep you posted.