Spine Damaged Due To An Epidural, Persistent, Swollen Nerves. On Regular Spine Stretching Exercises

Hi,
I've got an existing spine problem, my spine at L4 is damaged because of an epidural some years ago. Anyway, I manage this and continue with life the best I can - I have started to feel pain in another area of my spine now , in my middle back, it aches but is more of a sharp pain depending on my movement - it also pulses right in my spine. I often suffer with my sciatic nerves swelling as a result of the damage at L4 but this feels completely different -as in not disc or nerve related, but it doesn't feel like muscular neither - it's actually right in the bone??
I've been doing new exercises for the last 4/5 weeks which involves jumping and weight bearing and while I do make sure I'm warmed up and I'm careful (due to the existing problem) I'm worried this could be damaging me. I haven't done any exercise other than stretching my spine in the last 7/8 days and I'm not seeing an improvement and starting to get a little worried now.
I'm not overweight and I'm quite fit and healthy if it matters.