Another good cycling-specific book is Tom Danielson's "Core Advantage": https://www.amazon.com/Tom-Danielson.../dp/193403097X

Part of the book is devoted to the biomechanical theory behind the exercises, and was written by physiologist Allison Westfahl. It's very informative and well done, and agrees with other information I've stitched together from physical therapy and doctor visits. Danielson (the pro cyclist) chimes with various anecdotes from his experience. There are too many exercises in the book to realistically do them all, but picking out a few will help.

To simplify greatly, the core muscles control the position and rotation of the pelvis, which in turn affects the curvature of the spine. A weak core can lead to the pelvis moving too far (and spine bending too much) in the lumbar area, which can lead to bulging / ruptured discs, pinched nerves, etc. The location of the pain or tingling can be used to diagnose which vertebrae are affected. Depending on the disc injury, some people benefit from increasing curvature in the lumbar area, while others benefit from decreasing it. That analysis can then be used to develop a plan for therapy.

When most people think of doing core exercises, crunches / sit ups are the first things that may come to mind, but those are actually more harmful than good, due to the stress those put on the lumbar area and the overdevelopment of the abdominals. There are other muscle groups in the core that are important for stabilization of the pelvis. Many of the exercises require less motion in the spine than crunches, like hip bridges, squats, or suspending opposite legs while lying on the ground (and/or kneeling).

Other things that helped me were using a standing desk at work, and going on long day hikes. It took a few months of doing all of that stuff for my pain to go away.

When riding, I try to avoid bumps as much as possible, lightening up in the saddle when I see them coming. I also take Ibuprofen before starting a ride, to help counteract any inflammation that may want to start up.