Eating struggles

I’m so fed up with my sons eating. He hates it. Every meal is a screaming fit trying to get him to eat literally anything. He likes what we give him but he literally cannot sit for 5 seconds. I’m his high chair he screams bloody murder and tries to get out of it. In a kids chair at a kids table he just gets up and walks around and won’t touch his food. In a booster seat he scream and tries to tip the chair over, and throws all his food on the floor. I’m so sick of it. I worry so much about him not getting enough to eat and sometimes he’s so crazy it sends me into tears. I need help!