Hit myself in temple with knuckle hard 4 month ago last two weeks keep feeling lightheaded and dizzy could it be related? brain bleed? stress?

Post concussive: Trauma to the head can incur an internal shaking of the brain, resulting in microtrauma to cells and supporting structures. These can all combine into the "post-concussive syndrome". It does not require actual loss of consciousness. Symptoms can persist for weeks and can include dizziness and loss of concentration ability. A good quality brain MRI scan is helpful for diagnosis and evaluation.