I can kind of see both points - I ran myself into the ground with XW who had multiple affairs, stole money, etc, and I tried so "nobly and husbandly" to fight for her - while everyone told me I was crazy and to give up. But she was truly broken, and there was not a single thing in the world I could've done to bring her back, and it ended up costing me an additional 18 mo of my life just trying to heal from how her brokenness broke ME.
I would say the BEST thing you can do is let him go. For you and for him. The first time I let XW go in the midst of her cheating and lying and stealing, she became so jealous and came back so "DBing worked". The second time I let her go, I finally began to heal, so "DBing worked".
Either way, let go. Start watching a movie, and count off two hours of not talking to him or anyone about it. Then call a friend and vent. Then try to go 8 hours at work without contacting or responding. Then try a day at work, plus an hour in the gym. Then a day at work, a happy hour with friends, and an hour in the gym. I found breaking it up into bite-size chunks and slowly adding made it much easier.
I don't know what works for you, but find your formula!
