Everyone with bipolar is different, so I can only give you advice based on my experiences. Medication changes can be very hard. There are often side effects and mood is impacted. I know when I get depressed I avoid people like the plague. I simply don't have the energy to dedicate to relationships. Its one of the flags my friends watch for.

You can't fix it for him. All you can do is let him know you're there for him and keep reaching out to him. I know I am not always easy to love, but my husband has been loving me for 14 years.

Sorry I'm not more help, but I do wish you the best.