sometimes you just need to vent

Yesterday was a hard day. My little headaches are coming back and that just ruined my entire mood. I tried my hardest not to be a b**** to everyone who irked me, but that's a hard thing to achieve. Especially since I do live in this small ass four bedroom house with 8 other people, the majority of those people being moody ass people themselves.
On top of my headache problem...I've sadly ran out of weed a couple weeks ago and no longer have a job.
On top of all of that, I had a dispute with my two older sisters last week about my "laziness" and weed addiction. I am by no means lazy, as for my addiction, I admit to that, but no amount of b****ing and lecturing and making me feel like s@@@ will make me quit. Only I can make me quit. But they don't get that. Ugly things were said and I left. And I got laughed at as I left, like I was admitting defeat. I was removing myself from the situation cause I've been working on my anger. I don't LIKE to argue with my sisters. I don't LIKE harboring bad feelings toward them, but that's the point that I'm at.
My eldest sister is a coniving manipulative b****. I love her to death, but I'm not sure how much longer I can act fine and dandy when I no longer want to listen to her "problems" and give her sisterly advice when I already do so much for her when she has never done much to make my life a bit easier.
I was 14 when my eldest sister had her son at the age of 19. I had a huge hand in raising my nephew because his father wasn't there. I still help take care of him. Hell, I help take care of her now one year old daughter. Sure her father stuck around and he's a really great guy, but when he's not around its like a hastle for my sister to do simple things like clean up after her daughter, feed her daughter or simply play with her. I know my sisters loves her children, but she only interacts when its convieniant. And on top of that my sister loves to be waited on hand and foot. She's been that way for as long as I can remember. I'm over being her lackey but if I voice my displeasure its WWlll.
Right now my life is just too much. I have no job, no job prospects in this small ass town, I have no friends to talk to, no weed, no where to go to get away (I used to go to my grandparents house but my grandpa was diagnosed with throat cancer and cancer of the liver and I want to cry when I see him).
This is a build up of all the disappointments of my life, the struggles, the lonliness. I don't know what to do. I'm not some self-pitying suicide risk.
I'm a girl who feels alone and needed a place to vent so I coujld get these worries out of my head so I could stop being dragged down by this grey cloud and move forward.