Does your ex have a mental illness ? Is he seeing help, treatment?

Medications work differently for everyone.

If your son doesn't feel safe with him than you need to not allow your son to go there. Do you see a therapist? If not you might want to find one that can help you navigate your son seeing his father. Not sure how old your son is , he might need therapy.

I'm so sorry your having to deal with so much ((( hugs )))