In march I had a seizure and hit the right side of my head very hard. The next day I woke up with a black eye. It still hasn't healed. Will it clear?

Were there X-rays. You might have suffered a fracture over the zygomatic arch or over the orbit, and this could explain delay, but lingering symptoms could afflict the supra-orbital or infra-orbital branches of the trigeminal nerve. Best to get assessed by either neurologist, or neurosurgeon. Also, get help preventing future seizures.