Following measures would be helpful;
1) Back care in the activities of daily living:
a) Avoid activities which increases the pain.
b) Rest intermittently
c) Avoid bending at 90 degrees
d) Pushing and pulling should be avoided till pain subsides
f) Avoid prolonged sitting and standing
g) Avoid sitting or sleeping on floor
2) Anti-inflammatory analgesics like ibuprofen.
3) Local analgesic gels or sprays / ointment
4) Cold compresses
5) Electrotherapy like trans cutaneous electrical nerve stimulation: done by physical therapist. Other thing are ice packs, heating pads, electrical stimulation, phonophoresis, iontophoresis, relaxation, and biofeedback.
6) Lumbosacral corset or support or back brace
7) If obese or over weight, reduce weight for long term benefit.
You can start the following exercises;
1) Straight leg raising: Lie on the bed with your back and remain in a relaxed position. Slowly raise one of your legs upward and keep it as straight as possible. Count up to ten, and slowly bring down the leg. Do the same with the other leg. Repeat this exercise ten times.
2) Curl ups; lie on the back with knees bent, fold arms across the chest, tilt the pelvis to flatten the back, and curl-up lifting the head and shoulders from the bed / couch. Hold for ten seconds, then slowly lower to starting position. As strength builds, aim to complete one sets of ten curls. The exercise should be done twice a day (both the sets).
Please feel free for your follow up questions.
I would be happy to assist you further, if you need any more information.