You have annular tears that are causing your pain. The annulus is the outside of the “jelly-filled donut” (see https://neckandback.com/conditions/lumbar-degenerative-disc-disease-or-low-back-pain/). This annulus can be prone to tears and these tears can be quite painful. The tear never heals in any individual but some scar will form on the outside of the tear. This scar can stabilize the tear and make it non-painful. In some individuals however, the tears become quite painful and can take 4-6 months to “calm down”.
See the section https://neckandback.com/treatments/conservative-treatment-mechanical-lower-back-disorders/ to understand what biomechanics can be helpful to treat this disorder.
Planks are great when your back is non-painful but with an acute flair-up, this action will aggravate your symptoms. You need to back off for now. Epidural injections can be helpful to cut the inflammation and allow you to rehabilitate faster. Oral steroids for the acute injury can cut recovery time.
Dr. Corenman
Donald Corenman, MD, DC is a highly-regarded spine surgeon, considered an expert in the area of neck and back pain. Trained as both a Medical Doctor and Doctor of Chiropractic, Dr. Corenman earned academic appointments as Clinical Assistant Professor and Assistant Professor of Orthopaedic Surgery at the University of Colorado Health Sciences Center, and his research on spine surgery and rehabilitation has resulted in the publication of multiple peer-reviewed articles and two books.