@zeljko
I believe it’s the Valproic Acid that is causing the majority of your sons problems.
Sometimes it can be a challenge to find the right drug cocktail for seizure control with the fewest side effects.
Are your sons seizures both Focal and Generalized? Is the medication controlling them?
I wish I knew how to control his side effects without lowering dosages or changing medications but I’m at a loss.
Perhaps if you asked this question on one of the Epilepsy Forums someone there may have also encountered these issues.
Here are a couple links.

Coping with Epilepsy
https://www.coping-with-epilepsy.com/forums/
Epilepsy Foundation Chat
https://www.epilepsy.com/connect/chat
Epilepsy Action
https://forum.epilepsy.org.uk/
Jake