For what it’s worth, I have had back problems in the past too. I worry a lot about form, but I’ve found that doing deadlifts with good form and a challenging weight usually leaves my back feeling better than before, and over time as I have been consistent with deadlifts (and squats) I have been more comfortable, more able to maintain good posture, and overall less worried about my back.
I look at it like any other kind of training stress: some stress is good to disturb homeostasis and trigger supercompensation, while too much stress causes damage from which you can’t recover. Since my back problems were caused by my back being too weak for basic activities, maintaining homeostasis was not a recipe for healthy living, but at some point in the future it will be (and the degree of difficulty to disturb homeostasis will incur more risk).
On the other hand, early on in my back problems I started doing yoga, and would happily recommend it too. There is a yoga class and adaptations to the poses appropriate for just about everyone, with lots of opportunities to progress over time and do quite a lot to improve posture and ‘core’ strength in ways that will protect your back outside of practice.