Hello,
Do you ever smoke the weed yourself? I find I am quite a jealous person but it gets x10 worse when I smoke. Also, generally when I become jealous when not smoking it's because I'm not feeling good about myself, it has a lot to do with low self esteem and a fear of being hurt. In a way, it protects you, it drives people away so they can't hurt you...does any of this sound familiar? I would suggest counselling too, it has helped me in the past. Good luck x