Mom's I need help Desperately. 1 of my twins being the boy Caleb is having really bad tantrums... I…

Mom's I need help Desperately. 1 of my twins being the boy Caleb is having really bad tantrums... I mean really bad anytime and anywhere. To the point that on saturday i tried to go do grocery shopping and he was misbehaving so badly my mom had to take them out to the car. People were looking I was on the verge of tears. They're 20 months 18 corrected. I just dont know how to get it under control because he hurts himself and his twin sister and I or whomever is trying to get him to calm down. Its just really bad. Earpiercing screams throwing himself down on the floor hitting his head...hitting others....smh. Its draining