Since the terrain that most instructors teach is in about the same area. Can you kinda scope in on a class or two and watch the instructor for his 'stlye and technique' of coaching.
After seeing a Ins that you think is not a douche maybe approach him and talk to him a bit. Get his name incase you want to try him. Ask him how he goes about teaching an adult, kind of a mini interview before hiring him to help you.
Almost sounds like you should start over a little. Lock in the basic of getting your weight forward and using your foot/knees to initiate a turn. Build or un-learn some of the bad muscle memory you have now.
Just some thoughts, OH I started at 42 similar physical size. Took me 3 days of riding to become beginner proficient and a busted ass (tailbone) pain as I didn't know how to fall properly and if I did things happen fast not sure I would have been able too.
-I'm Slyder and I suffer from "Gummer Syndrome"