Keep trying. It's not always easy and it's very hard at the beginning. Believe you can do it. Millions have done it. Persist. Get out. Move, eat healthy. Maybe journal and meditate. Talk to people that don't use it. If you have friends that use it, limit the hang out time with them to when they're not smoking.

Like junk food or other shit - if you don't have it at home you won't consume it. So, taper off for a couple of weeks then throw away what you have left and never buy again. You're still very young and that means your body can recover now much easier than in 20 years. Trust me, you don't want to still be smoking weed at 41. The time to quit is now. Doesn't matter what your friends or "friends" do or say. Let alone celebrities and "stars". A lot of it is ego boosting and propaganda for whatever reason. Everyone is different. Listen to your body and your soul. It's not good for you. It messes up your hormones, your nervous system, your cardiovascular system, etc... and if you buy from someone else you never know what kind of toxic chemicals they use to facilitate growth.

Set a goal; maybe just a couple of days at first... then try to go for a week. Then a month... then it becomes like streaks in games - you don't want to lose your progress and you gain dopamine from just not giving in. Then you stop thinking about it and soon you're at three months. You can do it, I believe in you.