Seems like each day gets worse

Well I just found out that he's moving the skank into the house to help with the bills.  I am devastated to say the least!  I guess the last 29 years meant absolutely nothing to him!  How can someone do that?  How can he just forget the last 29 years as if they never even happened?  Am I missing something?  Is there a medical explanation for this?   Our 21 year old son is very upset but still can't seem to talk to his dad about how he's feeling about all of this and I'm concerned.  He's not a big talker and tends to keep everything in.  I'm afraid that one day he's just gonna blow!  I don't know what to do anymore.  I'm so depressed over this.  Just when I think I've been accepting things a little bit more each day, it seems like each day gets worse now!  I'm feeling so lost!