Concussion on oct, still having issues focusing on school work and developing headaches under bright lights in class. Is it still linked to the concus?

Probably. Your symptoms are typical of those of post-concussion syndrome. A new ct or MRI should be done to rule out a new problem such as delayed bleeding or hydrocephalus. Assuming this is ok, the symptoms should eventually subside. The duration is proportional to the severity of the concussion. You should be followed by a neurologist or other doctor experienced in treating post-concussion patients.
Linked to concussion. Unlike common thought the effects of concussion may last months to even more than a year. There are interventions available. You should contact a neurologist with experience in dealing with post concussive headaches and acquired attention difficulty.