I feel your pain because I have a similar situation. If I had known just how much the church condones adultery I probably wouldn’t have converted to Western rite catholicism. Needless to say, I no longer avail myself of confession at a parish where I had received that sacrament for 8+ years because that’s where the husband and mistress attend. (At the small parish where I attend Mass it’s hit or miss having access to confession at the scheduled time slot. Too often there isn’t a priest there to administer that sacrament.)
Both parish priests and my bishop weren’t too concerned with the situation. I guess its a fact of life these days. However, the lack of response by the church regarding the situation has completely chased my 4 young adult children away from the church. Of my younger 4, the two who are teens are lukewarm and likely on their way out of the church. The teen who was confirmed last year doesn’t want to attend Mass anymore and the next sibling down has no desire to go to mass either, nor be confirmed. The youngest two are too young to know any difference yet. But they like their dad’s girlfriend and have gone to church with him and her.
This isn’t an easy cross to bear and about the only thing that keeps me sane is the fact that the cross Christ bore to give me eternal life wasn’t easy for Him either. It was miserable and cost Him his young life. So I offer it up, trudge through it, ask God to give me a steadfast heart. I give God thanks for all he has done for me, and pray, pray, pray.
Many times I even wake up praying about the situation. I don’t know what to say other than hang on and do your best to maintain your relationship with God. I’ll keep you in my prayers.