Hi, Upbeat Girl
I can't tell you how happy I am that your son is accepting the fact that he may have BPD, realizes he has problems, and is willing to try to get help. That is a
major breakthrough, which I'm sure you already know

It seems like once you stepped back, stopped helping him, and let the natural consequences fall (whether you did that on purpose, or not), he reached his bottom and his new insights. I'm so
very happy for your family!
Now that he is in this new place mentally, if the momentum towards treatment and recovery continue there is so much hope for him. If you haven't already read it already, my own son's story (just click the globe icon under my Avatar, or the blue link in my signature below) is
very similar to your son's situation. And my son (36) is a real success story, after
years of drug abuse and addiction, living with undiagnosed BPD (he was diagnosed with ADD, Depression, Social Anxiety & Hyperactive Thyroid at almost 21), and suicidal ideations. Then, finally, after his last suicidal ideation he was admitted to a Dual Diagnosis Program where he was diagnosed with the BPD and started treatment for it with his recovery program.
If you have access to a Dual Diagnosis Program, I highly recommend it... . My son relapsed after 2 "normal" rehab stays (one for 28 days, the other 2 years later lasted 36 days), which he hated. He
loved the Inpatient, 21-day DDx Program because it treated his mental health issues first, then the addiction issues; instead of being treated as an addict only they recognized that he had been self-medicating his many mental health symptoms.
Please check out the
TOOLS and
THE LESSONS to the right-hand margin of this page like
qcarolr suggested... . I found this site a couple of days after my son was discharged from the DDx Program (they gave this site's webaddress with the discharge papers), and the information here is what taught me about BPD and sustained me in his recovery. It also helped me help him to do his recovery in the right way... . Please read his story if you can, because the similarities are so apparent to me that I think you could find hope there.
And, you will find hope here, too:
Good News, Breakthroughs & TLCs. And another thing... . my son also was a cigarette smoker, which caused him health problems and the family agitation. A year ago he started smoking e-cigarettes and I have to say, after the very first e-cig he actually stopped smoking altogether! He did try to puff a friend's cigarette just one time and couldn't stand the smell, taste and how it hurt his throat, and never puffed another time! He's not only been clean and sober from all drugs and alcohol for almost 11 months now, he's been off "real" cigarettes for a year!

Good luck to you and your son, and I hope things continue in the right direction for him forever... . Please keep us updated, Upbeat Girl