my sweet heart....your son should be your priority....your husband seems very insensitive and looking for excuses to get over the responsibility....
Probably, some therapy will help, if you can drag him into it....
I think you should talk to him and make it clear that your son is your priority and his life is important...and he's a kid, kids are making all kinds of mistakes....

Just keep in your mind that you can change a husband but you your son will be your son forever....

take care
Marjan