what should I put for my reason for leaving?

I lost my last job of 3.5 years at the end of October after receiving a dui in April, another in July, and a last one in October. It’s terrible I know, but not all of them were actually DUIs. I have since had the first one completely dismissed, the second one is going to Be reduced to reckless driving (court 1/16) as I was experiencing psychosis (first time ever, very scary, I went to the hospital and was diagnosed after I was released from jail), and the third one I am not sure will happen the court date is in feb. my old boss and coworkers want me back, I went to rehab for 45 days but our head of HR who fired me I just don’t know if it would even be worth asking.i worked at a medical clinic and my former supervisor suggested I talk to one of the physicians, but idk it’s so embarrassing and no telling what kind of rumors there are. My question is, when applying for new jobs and being asked reason for leaving I have no idea what to put. My supervisor and others will give me a great reference but I know the background check will be an issue. I did have a drinking problem but was not dui in the first two instances and I went to rehab and am sober since. Or what would yall do I can’t go without a job for much longer