Lack of Trust

Several years ago, I found an email in which my husband was communicating with a co-worker 25 years younger declaring his love. I confronted him and asked for divorce but he promised he’d change. She left the company and then a year later I found out they were still communicating as he was helping her with employment issues. The relationship was cut off (as far as I know).
Last spring, he started communicating with another 20-something woman in another country – similar situation. He excuses the behavior as “helping her with career advice.” Again, I found out about it and friended her boyfriend by mistake. It caused all kinds of issues and they don’t communicate any more.
My husband has bi-polar and chronic pain. His other two siblings divorced and remarried and his dad recently said, “We don’t need any more divorce in our family.” He knows something is up with us as we don’t laugh and hold hands like we used to. I don’t trust my husband. We went to counseling after the co-worker issue which helped for awhile.
Next month, we are attending a marriage retreat with a counselor. I’m curious to see what will come out in the sessions but honestly, I’m exhausted and just want to make a decision. I’m not afraid to be alone but I’m worried about how my grown boys will react if we decide to divorce.