Nearly-3 year old makes most things absolutely miserable

Please tell me this gets easier. My son has always been strong willed and stubborn. But lately it has become miserable to be around him. He fights everything. Eating is a fight. Taking a bath is a fight. Going from one room to the next is a fight. He screams constantly. Hits me. Hits his baby brother. If I take him somewhere like a store he screams and cries the entire time. If I take him to a park he enjoys himself but leaving is like trying to wrangle a shark. He gave me a black eye just because I told him he had to wash his hands. Idk what to do.