Back pain (SI joint?) to the left of spine at belt level in healthy 26yo male
I have had back pain for about two years that seems to be originating at the belt line, just to the left of my spine. Because of that, my whole lower back is tight and painful.

The pain is worse with bending (such as to pick something up off the floor) and is pretty well always present.

I also have noticed a little bit of numbness in the toes on my left foot, although most of the time it is very minor or undetectable.

I'm not sure if any one traumatic event caused the pain. I'm healthy and active. I play softball, volleyball, and I work out. I can still do all these things; it's just the sore back sometimes bothers me or is aggravated if I jump or dive or something.

I'm 6'2", weigh 195, and I don't smoke or drink.

I had an X-ray of my back which the doctor said was normal. Also, when mentioning the pain to the doctor and describing the area, he mentioned it might be the SI joint.
I have tried a handful of stretches and exercises that I have found online for low back pain, but so far. nothing really seems to hit the spot.

I can't really afford to get an MRI at this point, which is what the doctor suggested as a next step, so I'm trying other methods to figure out what might be wrong and what can be done to help it heal.

Thank you for your time!

Luke