Unhealthy Relationship??

So me and my boyfriend have been together for about 3 years and I love him to death but lately we have been fighting a lot. When we first met, it was wonderful but at the time we were still in high school. But due to issues at home with both our parents, he ended up getting his GED and and I started college and we moved in together to avoid our parents. (Mine are going through a divorce and I'm in the middle while his dad is on drugs and his mom doesn't care she just spends his money all day) so after a year I guess to deal with depression he started doing drugs more like smoking weed a lot and occasionally sipping lean.. I got him to stop the sipping but it's like he's not motivated anymore. I'll be finish school in a year once I pay them off but it's like we fight all the time because he's unhappy. And I know times are bad rn because of the stress our parents put us in but idk I just want us to stay focused and we just always are arguing because he can't see my pov .. I just don't know how he'll understand that priorities come first and I don't want to break up wth him over the smoking because I smoke too but I can maintain while being a smoker...