Hi Jade,
This is a tough question and I understand the "feeling like a horrible person", because I had to do it with my son. I cannot tell you what decision is best for you, the only thing I can do is share my story, why I did it, and the outcome so far.
My son has been arrested and convicted three times. The first two times I bailed him out, helped him get to work, provided a job, provided a place to live, tried to keep tabs on his behavior, provided money for probation, paid for more college, and "helped" out as best I could. I did this because I felt guilty, and that I had somehow contributed to his "problem". I married an alcoholic, I didn't leave his father soon enough, I didn't do an intervention, I wasn't a "good enough" mother, etc.
In other words, I blamed HIS problem on MYSELF. I was being co-dependent as hell, enabling him to continue abusing, and providing excuses for HIS behavior.
This past spring, he got arrested for the third time. This time: I did not provide bail, I fired him, I moved his things out of the house, did not help with his attorney, did not pay court costs, didn't go to court with him, etc. I told him I loved him, but his behavior was unacceptable and he could no longer participate as a member of this family until he was not using, treating for addictions, and employed.
Of course the initial response was horrible. He tried to guilt me, use my grandson as a weapon, pleaded, cried, begged, got angry, etc.; but those were the boundaries and I didn't back down. It has been a little over six months and he is clean, he voluntarily enrolled in an intensive outpatient program, has a job, and attends meeting seven days a week. Some of the meetings are required as a part of probation, but the others are on his own.
Christmas will be the first time he has participated in a family function. He and my Grandson are coming to my daughters on Christmas Eve for dinner. So far he is improving, but I also know it is too early to get my hopes. In his case, I have to take it day-by-day, but so does he.
Jade, I hope this helps. Yes, I still feel "horrible" at times, but mostly that is my own guilt. But the guilt is my problem, not his; and I know my attempts to "help" really were "hurting". I just need to remember I did the best I could at the time, so there is nothing to feel guilty about. I didn't do anything wrong intentionally. Please try to remember that for yourself, so you can save yourself a lot of unnecessary pain.
I hope you find peace with your decisions.
Debbie