Low back pain is the pits. But there are lots of things that someone can do on their own at home to help. Stretching for one. The hamstring is often tight when someone has low back pain. Stretching the ham string muscles regularly will often relieve pain in the lower back. Stretching the low back muscles themselves helps. Light weight lifting and things like doing the super man mat move will strengthen the back overall and you need good ab muscles to help with good low back muscles. Lots of youtube videos for this. Ibuprofen always helps in the short term.
When you first have pain you have to slow down, rest, then start range of movement exercises and stretching, and then move on to strengthening exercises after the pain eases. This is basic physical therapy. This has been going on for awhile, so I'd think it's time to see your doc and then get referred to physical therapy. What they will have you do depends on what's going on, so an MRI might be ordered for you. But most likely it's a muscular thing that can be worked on in PT.
Low back pain often occurs because of the tight hip flexors. These are muscles which support spine at the lower area? they help you to balance, sit and stand and support the core of your body. There is a great exercise program which i found on the internet, called Unlock your Hip Flexors and it really works. No more back pain. I advise you to try it.