Back pain I've had back pain that started in high school. I was always an athlete and always active. I never hurt my back or had any type of accident. I am 33 years old now and still have the same problems. I've seen doctors about it and they cannot f

Most. Most cases of low back pain can't be tied to any particular problem. The majority of imaging studies in people with back pain are either normal, or show abnormalities seen commonly in people with no back pain. Only a minority of back pain causes are something that can be "seen" on any kind of imaging, and that's why mri's are often not very helpful for back pain. Many cases of "nonspecific" back pain are due to issues with muscle imbalances, chronic strains, and sometimes postural or orthopedic abnormalities. These frequently respond to physical therapy, and this is something you should definitely try if you have not already. Massage can be helpful for at least some cases of back pain, and response would tend to imply a muscular cause. If you don't have an obliging significant other, seeing a professional massage therapist may be worth a try.
The. The previous answer is true. There are many potential sources of lower back pain. I've have seen misdiagnosis very frequently and it is absolutely shocking how often it occurs given the frequency of lower back pain. You have seen many doctors, but as you know, not all doctors are the same. Even with the same board certification and training, they vary quite widely in their ability to differentiate between minutia. I don't know if this answer creates more confusion for you, but I would highly recommend vetting out a true spine and pain specialist to see if something is being missed. In any case, core strengthening is recommended.