Relationship advice

So I been with my boyfriend/baby daddy for almost 3 years. We are 19 y/o. I'm 31 weeks pregnant and we only have 600$ saved up (from me babysitting) my bf can't keep a job. I can't work because I'm pregnant so I'm depending on him..we live with his parents who support us I feel like he thinks they are always gonna support us but me on the other hand I'm very independent and I wanna care for my child no one else..anyhow my problem is he spends all the money he gets from his parents or selling things on weed. And he always wants to eat out and spend money and it stresses me out. I knew when I met him that he was a pot head as I smoked with him too but now we have a baby and I feel like we should be saving every penny for our little one. Any advice? I try talking to him but he says I'm making him unhappy and "causing him to smoke" & I'm annoying. . . Any tips? ?? Hellpppppp