I'm in AA, & our steps are big on "making amends" to people we harmed during our drinking days. We try to view "making amends" somewhat differently than "apologizing." Sure, we formally "apologize" to people, but given the damage we sometimes did while drinking, folks sometimes continue to maintain a distance. "Amending" something means to make a change. In AA, we do that by staying sober one day at a time so we don't make the same mistakes over again.

I realize this isn't the addictions support section, but to my mind, it might be helpful for you to view "making amends" for your untreated BD behaviors in a similar light. I know I hurt others when I was untreated, or would play with my meds. I lost friends due to my BD. I try not to beat myself up, though...or to apologize again & again. I'm "amending" things by following a treatment plan & trying to stay mentally healthy one day at a time. That's all I can do.

Alcoholism & bipolar disorder are both diseases. I don't think we'd feel a need to repeatedly apologize to people if we had Parkinson's, or some other disease. It's very decent of you to touch base with old friends, but the past is the past. Perhaps if you try to approach them as the healthier version of yourself that you are today it will relieve you of any discomfort you might have about approaching them. You might wind up feeling better about yourself, too. Just some thoughts...