So ashamed of my response

This is my first post. I have never had any issues, I am 60 years old and married for 19 years. My wife's son from a prior marriage is 21 he is Bi-polar, wont work, stays high on different drugs all day, has serious anger issues and can get violent during these anger episodes. His father called us aprox 1.5 years ago and said that we was living in crack houses and he thought that if he moved out here with us, things might get better because we live in another state so we agreed, I have asked him before if he could help out around the house by doing little things but it has gotten to the point that I live in constant fear, this young man is much bigger than I am. 2 months ago, my wife and I were in our bedroom talking and he thought we were talking about him, he busted through our bedroom door and grabbed me and put his arms around my neck, and started chocking me, he finally let go but I was really traumatized. He refuses to take any of his meds, he spends all the money his father sends him on different types of drugs instead of his medication. With all of this being said, he had an issue with his car, he is no mechanic but he attempted to put a water pump on it 2 days ago and broke one of the bolts off into the block, he immediately became a powder keg, called me crying so I told him not to worry, I took off work early, went home and fixed it. My wife came in an hour or so later with Taco Bell. He won't eat vegetables so she orders his without, well, the order got messed up and there were vegetables on everything. While my wife got upset and had a few choice words to say about Taco Bell, He got extremely upset, angry and started calling her a b_ _ ch and cussing her at the top of his lungs. I was sitting on the couch between the 2 of them putting away my tools. She went to the bedroom, away from the situation. he walked into the kitchen. I stood up, took a few steps towards the kitchen slowly an said, come on man please don't talk to mom like this at which point, he lunge at me screaming again, like he had done before in our bedroom. I had one of the tools in my hand and I blindly swung it at him hoping that he would back off but he didn't, in retrospect, I guess I should have just allowed him to jump on me, because he did that anyway. he was actually hit by the tool though and required some stitches and now he is threatening to kill me..... I feel so ashamed of reacting the way I did and don't know what to do now. He left this morning to go back 3 states over, to stay with his father but I feel just horribly ashamed of my reaction and I just don't know how to get past this.

Depressed

Okay, i have to say that as I read this I was going to put you up for a nomination for saint hood. I was waiting for " the big moment" you were referring to.
Well I read it and maybe not sainthood but dam close.

You can only help people who want to be help

This person is not just bi-polar but also has a lot of personality problems. I am sorry for your wife but with drug addicts sometimes there can be no saving them. Next time don't take him back unless he is in rehab, or with a job.

You and your wife deserve some happiness and nothing is worse than to live in fear in your own home.

You stood up to man half your age, bigger than you to protect your wife.Put yourself in danger. Good on you. I hope she understands what you were doing.

I wish you all well, but sometimes they have to help themselves first.

Sometimes having severe consequences will get addicts to finally realize that things can't continue the way that they have been going, sometimes not.
I know that the possibility of going to prison stopped me in my tracks. I wondered how my life had gotten so unmanageable. I never wanted it to get this bad. I sought treatment.
I would like to say that it worked out the first time and things got better, but they didn't. I glimpsed that spark of recovery, but drugs and alcohol weren't done with me yet.
It took a few more years and a few more failures and a few more tries to catch and hold on.
The statistics for recovery sucks. Only about 4% make it. Late-stage drugs and alcoholism only get worse and more difficult to treat. Bi-polar conditions can't be treated in an active drug addiction situation.
I hope that your step-son tries to do this for himself. Recovery generally won't work if it is someone else's idea or it is mandated. You can certainly support his wish to get help.
I heard what I needed to hear that granted me my epiphany in rehab and the rooms of AA. I have 28 years clean and sober and stay that way by sharing with others about what it was like, what happened and what it is like now.
Best of luck to all of you.

Thank you for the responses, I have had a bit more time to actually think about the situation and am starting to realize that the issues that I have experienced with this young man were pretty much unavoidable. He refuses to get help and there is nothing that I can say or have said that seems to make any difference... He is gone now but hopefully will seek help at some point.