Get evaluated. If you have sustained a concussion, you should be seen by someone trained in the evaluation and treatment of concussions to screen for more serious injuries and monitor your healing progression. Absolute rest (dark room, no stimuli) is the best initial treatment for a concussion followed by a gradual resumption of activity as absence of symptoms allows.
Get checked. If your brain has not fully recovered from a concussion, you can continue to have ongoing problems. After a concussion, your brain needs complete rest. If you place strain on your brain before it has healed, your symptoms can worsen. It would be good to get evaluated by a neurologist.
Evaluation. More and more is being learned about concussions. Obvious symptoms may include fatigue, nausea, blurred vision, pain upon light exposure. And headaches. Subtle symptoms include " muddy thinking", slow reflexive response, poor school work etc. Final resolution may take months. There are validated tests and specialists for proper evaluation and they should be used.
Work with PT/OT. The post-concussive symptoms of dizziness may be very uncomfortable. Physical and occupational therapists have specialized training to help with this. Work with them to build up your confidence and to overcome the symptoms of dizziness. That will ultimately help with the psychological issues.