For the record, this is what a good physical therapist would have prescribed.

The issues that come from running are related to where you start from lacking knowledge and lacking physical health. Knowledge guides interpretation of pain(what different types of pain mean, when to stop when to push through). Understanding pain is a communication skill that very few people will teach you, but in my opinion is more valuable then literacy. Knowledge also enables positive feedback loops concerning form and efficiency of movement.

Physical health is the structal integrity of the core and stabilizer muscles. Each of these items are on a sliding scale, and somewhere in that scale is a tipping point where if you pass under it you are hurting yourself instead of healing yourself. I hypothesize that 80% of our population falls on the injury side, but that this could be solved with education and PT.

I'm glad you didn't give up, or had the nerve to push past anyone saying "that's just the way you are, you can't fix that" because I feel that statement couldn't be further from the truth.

Do some strength training and some playful sport instead, like basketball or BJJ. It's fun, you'll look good, you'll move well, and you'll get confident with people, all in 2-4 hours per week.

You also need to do some kind of strength training. A push, a pull, a spinal compression and a spinal tension. Eg pushups, rows, squats, pullups.

Otherwise your core will be weak and you will be missing key stabilizing muscles that prevent injury when you are in an unusual position, like picking up a suitcase or changing a tire. Which is exactly what causes back pain.