Turn the seat off bouncy
Like a lot of others on here I have the same lower back problem. Too many years spent outside in all weathers delivering coal or changing wheels, back springs etc. Fortunately retired now.
I would go to an Osteopath, Chiropractor or Sports Injury Clinic. Ring around a few and see what they charge, the osteopath I go to charges £35 for the first consultation then £30 after that. Any problems usually sorted after about 3 / 4 sessions.
My wife goes to the same clinic every 6 weeks regardless for a check up and massage. When she first had problems a few years ago she initially went to the GP but after 3 appointments he advised to see an osteopath!!!
As previously mentioned laying an ice pack on the problem area for ten minutes a day can bring some relief until you get some professional treatment.
Tyneside
If your lower back pain is ok during the summer months and only starts to be a problem come September/October you may need a dehumidifier in your bedroom so that your mattress doesn’t get damp from the damp air.
Make sure you get a dehumidifier that has an adjustable knob. That way you can adjust it so that is doesn’t stay on all the time, which would waste a lot of electricity and therefore be quite expensive to run over the winter.
Every home should have a dehumidifier, because it’s an efficient way of drying clothes in the winter. Not needed during the summer.
If you are spending too much time driving and not exercising, you may need to change your job to store delivery work. This will get you out of the driver’s seat more often and give you regular exercise.