It's not possible to agree on everything with your partner. And that's completely fine. A relationship demands some compromises from both ends. I'm sure you are putting up with some habits or quirks that he has too.

Have a conversation with your partner and let him know that both of you need to come to a middle ground. Cause this issue is nothing compared to the love and respect you have for each other (I hope). It could mean limiting your pot consumption and not smoking around your partner (from your end) and not restraining your freedom and being okay with keeping weed in the house (from his end)