My question involves criminal law for the state of: SD
Previously i was jumped by 3 guys with bats and was injured, 2 of which were charged and are waiting for court. The 3rd guy they could not prove was there. Later on i was drinking at my house and the third kid shows up at my house were my friends and i were drinking in the garage. I go straight up to this guy and tell him to get out of my house afraid he may try to cause trouble with me. This guy i believe is a drug user and is mentally unstable. Instead of leaving he chooses to ask me what he did. I tell him he knows what he did and repeat for him to leave my house. He then gives me a look like whatever and starts pulling his hands out of his pockets. I'm afraid of what he might do so i punched him. he starts stumbling and i hit him until i put him in a headlock and take him to the ground. I'm holding him on the ground and tell him ill let him go if he promises to leave. He says he would so i let him go and he leaves. On his way out he says hes gonna go get his friends. About two hours later the cops come and arrest me for simple assault and inform me he has a broken jaw. The court then indites me for aggravated assault. I believe because i thought of him as a threat i can prove self defense. What can i do in my situation?

