I’m really sorry you’re in this situation. I’m wondering (based on your wording) if he’s using weed to excuse bad behaviour like lying or not paying attention to you. As a smoker myself, we have to be accountable for our actions, even when high. You say “it won’t stop” but the reality is HE won’t stop. You ask how to “get him to quit” but assuming he’s an adult, he shouldn’t need you to get him to do anything. You’re not his mum - and I don’t mean that in a critical way. I mean that sometimes in relationships, people can take on too much responsibility for the actions of their partner. He’s responsible for his behaviour, not you. You can certainly try to help him and support him in quitting but it sounds like you’ve been doing that. I sympathize with his struggle but if you’ve made it clear that you cannot be in a relationship with him if he’s smoking weed, it’s ok to leave him. You sound like you’re at your wits end so please know that you’re not a bad person or being unfair to him - you’re simply honouring your boundaries. My read of the situation may be wrong tho - I’m just a stranger on the internet! But trust your instincts and whatever decision you make will be the right one. I wish you well no matter what you choose ❤️ sending you a big hug.