Reads like a herniated disk somewhere in the ballpark between L5 and S1 that is putting pressure against your sciatic nerve that leads to your leg. (one each for each leg)

Rest your lower back as much as possible. Do not target train the area till you've gone 2 weeks without the discomfort. Even then, begin very light...so light it almost seems stupid.

Do not sleep on your belly, this puts enough strain on an injured lower back to prolong the discomfort. Best to try sleeping on your back with a pillow under your knees.

Take an anti-inflammatory med before bedtime, and another when you wake. FYI...you still have to remain conscious of there being an injury, just because an anti-inflammatory relieves the pressure is not an indication of having healed, its just a means to help the process of healing begin.

Hot compress to encourage blood flow to the area which helps with healing. Followed by cold compress to help reduce swelling. (or is it vice versa?)

Learn and practice good lower back stretching. (google it)

Get your abs strengthened to help alleviate stress on your lower back.

If you've a long-term, semi to permanent injury...exercise will be key in keeping it at bay. Walking is great...swimming is even better...running is a no-go.

And lastly...believe it or not...being seated puts gobs of tension on the lower back...get off of that chair you're on and get a lumbar support cushion for your driving and PCing.