I got this pot dealer i know to get me some weed i spent $200 he didn't get it but says he will get my money..?

Was buying the weed for me and my friends for a festival, i stayed up late that night waiting for a message to tell me he got it turns out he messaged me 10 mins after i fell asleep. He didnt get it in time and we went to the festival and had a great weekend without the use of or maybe a little bit of marijuana.. After the weekend i got back and decided to go pick up my package or see if he would give my money back. He says he got jumped when he was in town selling weed and he had my package on him.... it is now three months later and after continuously being messed around by this guy i am very stressed. The type of answer i am looking for is not some kind of drug psychology or some ghetto ways to get back at him, i wanna know how i can stop thinking about that money while maintaining my hold on him. At the moment he doesn't know what i am capable of so he is still trying to get my money, or so he says. BUT i cannot stop thinking about it, it is ruining my sleep at night it is interrupting my schoolwork and i am starting to think of doing horrible things to him to get him back. Please someone relieve me of my stress!! btw i know i shouldn't smoke pot while at school but honestly i am doing fine at school. I only smoke pot about every 2 weeks as a stress reliever, i am always cautious when smoking pot and i'm not an aggressive individual.