I have severe lower back pain when i bend over, lift things, lay down flat on my back, sit for to long, stand for to long that has lasted for 2 years?

Many Possibilities: Depending on how long it's been going on, i would consider an evaluation by a spine specialist. Sometimes it could be a muscle imbalance, early onset arthritis or scoliosis. Also could be a pinched nerve/herniated disc. Either way it might be good to figure it out and get appropriate treatment.

MRI?: If you have pain radiating into your legs, or you have numbness, tingling, or weakness in your legs- you should be checked out by a spine specialist and likely get an mri. Even if you don't have symptoms in you legs, assuming you have tried conservative options, you should probably get looked at by a pain specialist or physiatrist, and still possibly need an mri.