Am I holding on for nothing?

[Amanda]

I just need an outside opinion...
I've been in a relationship for seven years and have lived with this person for six of those years. When I first moved in with him, I didn't have much, he was making good money and took care of me while I went to school for years. He never blinked an eye (only held it over my head once during an argument).
A few years later, the tables have turned. Once I finished school, he got laid off and for the past few years I've been supporting him. If it wasn't for me getting an amazing job, we'd be homeless. The first year of unemployment, I was patient. He'd get odd jobs here and there and was getting unemployment. For the past year he's been leaving jobs so easily an quickly knowing that I need help with rent and has only used social media to find a job. He smokes weed and was not physically going out to find a job an when I would come home, all his buddies would be here and I'd get SO pissed. He doesn't have anyone else so I stuck it out with him (after walking out on Thanksgiving,but then returning).
He now has an okay job and seems to be picking up the slack. But for how long?
I always try to remember what he did for me, but there was a lot of hurt along the way (such as cheating and he gave me an STD). Also a year ago, I developed a heart condition and he's been so great taking care of me.
I've been nothing but a gem to him, but he never communicates with me about the future, and when he does I cannot take him seriously. Am I crazy? Should I leave? It's really hard to tell. Anyone in my shoes that wants to share their take on the situation?