Can magic play a role in what I did to the man, in terms of lying and dishonesty? Will my repentance be accepted, given that the rights of people are still hanging over me? Or is it a psychological illness? Or am I simply a bad person looking for excuses?

If the husband mistreats his wife, he is mistaken and disobedient to Allah's command. The symptoms mentioned might be due to magic (sihr), and the best treatment for it is ruqyah according to Sharia. Being afflicted by magic does not negate accountability unless it leads to complete unconsciousness. You must repent to Allah from the forbidden relationship with the young man, for he has no right over you. Psychological factors might play a role in seeking affection outside of marriage. Reconciliation between the spouses is advised; if not possible, then separation with kindness, as divorce can be a benefit in some cases to end corruption and harm.