My husband wants a divorce and to terminate his rights

The last 3 years have been super hard on us. I had a mastectomy, going through infertility, husband had a TBI.

We’ve recently been having very bad nasty fights. It’s gotten to the point we both consider divorce. However my husband claims he’s not interested in co parenting. He said he will sign away his rights. This is just so crazy to me because he has always been the best husband and father. He is my son’s best friend. Very active . This fighting and so on is not normal. We are usually quick to forgive and talk through things…. If divorce is the answer I can accept it but him not being in our son’s life? My son is 5. This would be horribly traumatic. All because he doesn’t want to fight the different life styles. He doesn’t want resentment between us. I told him I want to find a way to work through this and come out as a family, or to be healthy co parents. He just doesn’t have hope in us anymore. I don’t know what to do