I hurt my back a couple of times over the years between squats and leg press. Each time I went to the doctor, they pushed chiropractor or the physical therapist. PT was useless the 3 injuries that I went for, and Chiropractor maybe helped once.
When I went and read a lot about muscle and back injuries, it sounded like the ubiquitous advice of heat, cold etc can still be used. BUT what really helps is to rest for a day or two to offset some of the bigger damage and then get back into the gym at very low weight and start over.
If you haven’t ripped something to the point of surgery, there is something about keeping active, keeping blood and nutrients flowing to the site that maximizes healing I guess. I was back to where I was squatting within 2 months and my form was better than ever with a lot of attention paid to my back.