Sorry about your back, sounds terrible. Anti-inflammatories such as ibuprofen can help (Advil, Motrin). Take with food. There are plenty of stretches that are recommended that might be helpful, just...
Forum is really quiet. I think I have some room for a couple more benches.
https://forum.bodybuilding.com/attachment.php?attachmentid=9391183&stc=1&d=1646486017
Nothing beats selectorized, except when you have to move it. I could replace my cybex kneeling leg curl and nautilus leg extension with this one but wouldn’t save space. And less equipment.