I have been a single parent, and I have remarried as well during my son's youth. I have given him the best I could. I co-signed for vehicles, let him live rent free with me until he was like 27! I have given him money, paid his cell phone bills, and anything I can. A few years ago, he started talking to me like I was dirt under his feet. Everything is my fault, or other people's fault. He's quit countless jobs because somebody did something he didn't like. He's had many girlfriends, but nothing over a week because he's got a strange sense of humor (almost hurtful), and bossy-temper issues. He thinks he can tell me what I should do, spend, where I should go. He's in my business all of the time. We fight a lot... more and more lately. My mother passed away three weeks ago and I am still devastated. He is still treating me horrible and saying things that are even worse. A freund told him maybe I needed him to talk to right now because I did lose my mother. He told this friend, "Hey, what am I supposed to do? Life goes on". Well, I heard that tonight, and after the verbal abuse, using, stealing from me, threatening me, and all the other stuff. That was the unfortunate last straw. He's 31, can't hold a job or girlfriend, talks about me like I am his most bitter enemy, hangs up on me, won't call back, calls when he needs something and when I don't have it to give, he yells at me. I have decided I am done with this man. I told him that I do love him, always have and always will, but I am done. I told him to get anything of his out of my house, turn in his key and keep in touch now and then. I have tried EVERYTHING, and I can't make him respect or love me and I am to the point now that I am afraid of my own son. It's heartbreaking, and I never thought it would ever happen, but here it is. I have suggested he seek counseling and even get checked at a doctor for some stress related, or even mental, disorder. He started using cocaine, and he drank until he was stupid on a daily basis. Well, horrific, painful ulcers have forced him to stop and it gets worse all of the time. Am I right, or wrong about just letting him go his way while I go mine? What more can I do? I have money enough to pay my bills and nothing more. I have no money to get him medical coverage, and if he were anyone else, I would have never taken this verbal and mental abuse as long as I have. I just want to grieve my mother's loss, pick up my life, and be happy again one day without being tortured by a son that seems for all practical purposes to hate my guts.

Sounds like you are doing what you needed to do about 9 years ago.
I don't want to sound preachy here but by letting him stay all the time, giving him money, you have allowed him not to work steady.
* girlfriends are his own issues.

So he wants to blame someone else for his problems, does not want to take responsibility. So it is time to let him sink on his own some.

As most often, I agree with Fr_chuck but wanted to add

A. if he were anyone else, I would have never taken this verbal and mental abuse as long as I have --and keep in touch now and then --You are much to generous--

B. You can tell him "WHO has their life together and WHO doesn't and
YOU are going to tell me what to do and how to do it when YOU can't even
Get it together yourself?

C. Am I right, or wrong about just letting him go his way while I go mine? What more can I do?
Yes you should have done that years ago as Fr_chuck said.

D. Cut your apron strings and let him learn the hard way that he had it much too easy
For the disrespect he gave you.

He doesn't hate you, he hates himself. Leave him to sink or swim on his own, as you have done more than your part. He must work on himself, and you cannot interfere in his "growing up", so go about your life, and pray for his, but do nothing.

I agree with Taliman often when people are miserable with their own self they take it out on the one closest to them. He needs a reality wake up call and he will never learn to respect you or appreciate you as long as he has it so easy. He needs to be on his own, make it on his own to the point you can say WELCOME to reality!
You don't need to cut the apron strings -YOU NEED to BURN the apron.