Being afraid of re-injuring yourself is not uncommon. You know how it feels to have a sore back and you want to make sure you don’t hurt it again. Unfortunately, as you’ve learned, this can backfire on you and the more your worry and try to protect your back, the worse it can actually make it.
It may be worth visiting your doctor and discussing your concerns. There are some programs that help people learn how to deal with their fears, lowering their pain.