Hello, I’d like to help you with your question.
It sounds like your son may have either PTSD or he could have a serious mental health disorder. It is difficult to tell given how he is reacting, but his feelings towards you as well as his inability to manage his life at this point says that he is bothered by symptoms bad enough to keep him from helping himself.
His reaction to you may have to do more with the past and his father than with you. Sometimes, when a person has a difficult time in childhood, they tend to blame everyone instead of just the person who hurt them. They feel enough pain that it is too difficult to separate their emotions out so they end up feeling angry and hurt in general.
Helping your son may be hard due to how he feels about you. Even if it is unwarranted, he may resist help just because you suggest it because of his feelings. In order to get him help, the suggestion may have to come from someone else. What you may want to try is seeing if he is willing to see his doctor instead of a therapist. If he would agree, you can contact the doctor ahead of time and let them know what is wrong. Sometimes, a person will listen to a professional, even over their own family.
Another option is to see if he is willing to try self help. It is less intrusive than therapy and can set him on the right path. A book, self help group or resources on line may help.
You can also try asking a friend of his or a trusted family member to intervene and talk with him. He may listen to them.
If all else fails, you may want to try an intervention. An intervention involves family and friends gently confronting the person with their concerns in an attempt to break through denial and help the person see they need help. Most interventions involve alcohol use or drugs, but it can work as well with mental health issues. It is best done with a counselor involved, but you can do it without as long as you know the guidelines. Here is a resource to help:http://www.originsrecovery.com/how-to-plan-a-successful-intervention/
The best thing you can do is to be there for him. However things turn out, he still knows to come to you for help even if he is difficult to deal with. So you are important to him.
I hope this has helped you,