What to do?

Brogan
Me and my boyfriend have been together nearly 3 years and I feel stuck. He hardly works, never wants to do anything, smokes a lot of weed, doesn't seem to want to achieve anything or move forward in his life. When we met I was 17 and he was 18, now I'm 20 and he is 21. I am trying to get myself together and feel like he is holding me back, which makes me really upset. 
What should I do? I love him to bits, he is my best friend, but I feel like it's time for me.