Is this a reasonable request? ?

My partner smokes weed. He holds down a full time job and he has cut down on the amount he smokes but for me I want him to give it up completely as I don’t want my kids to grow up in a household where their father does drugs that they may some day find and use or think this is normal and start doing it. I used to smoke weed it made me lazy and basically was a waste of time and money. I gave up and gave up easily. He told me before he would do anything for me but when I bring this up he gets angry and screams and says I don’t make you give up stuff i am a hard worker etc. I feel like weed is much more important in his life than I am. I think I need to break it off I’ve been with him for 8 years and have wasted that time now I’m probably too old to find love again I’m 27. What should I do I definitely feel second best to a drug which is very upsetting.