What Are The Symptoms Of Minor Head Injury And Concussion?

Four days ago I hit the right side of my head (over the temple area) extremely hard on the top of my car while attempting to squeeze in through the tiny space left for me due to a neighboring car parked too close. Keep in mind I have a higher tolerance for pain than average. Immediately after smacking my head I had a bloody/metallic taste in my mouth with no visible bleeding present from the mouth or ear. Tears kept rolling out of my eyes uncontrollably. I instantly got a throbbing headache and felt slightly lightheaded. 5 minutes later I became nauseous but never vomited. I did not lose consciousness. I tried chewing on the right side of my mouth an hour later and was unable to secondary to pain around the temporalis muscle. I have especially bad vision with sensitivity to light already before the injury, therefore I cannot confirm vision changes, although I have noticed blurred sight in my right eye only after several hours of being awake everyday, not sure if that s related to the injury though. Mild anxiety and concentration problems already existed before injury. Currently, I have a slight bump and moderate pain and tenderness upon palpation of site of injury. A nagging/aching headache persists which temporarily goes away with Ibuprofen but comes back within hours. I am unable to sleep on the right side due to pressure on the bump . Based on the symptoms is it at all possible I have a concussion or a very, very minor brain injury or am I overreacting? Seeking medical attention will be a very costly situation for me due to my awful insurance policy and is my last resort.