Could scoliosis cause mild to severe back pain and severe tension headaches?

Yes. It can, if coupled with c-spine or thoracic abnormalities, contribute to uncontrollable repetitive movements. You need to be seen by a good Neurosurgeon who can evaluate your cervical thoracic and lumbar spine. I suspect there will be other findings beyond the scoliosis. Good information is available at
Sometimes. Patients with moderate to severe scoliosis may develop pain as they age. Depending on the location of the scoliosis and the physical fitness of a person this pain could be mild to severe or contribute to headaches.