If you are grossed out by stuff stop reading this right now, if not continue...

My sister is a dirty disgusting selfish lazy human being and I can't take it anymore. I've put up with her leaving tampons in the trash and them becoming gross and moldy because she doesn't take it out or tell me about it, I've put up with her leaving gross stinky partial beer filled beer cans all over the house. I've even put up with her mountains of cigarette butts everywhere but a decaying stinky fish that died almost a week ago left sitting in a cup on the counter is the last fucking straw. I'm the bad guy in all of this because I told her to stop playing candy crush and deal with it like she should have done in the first place, but no I'm the bitch because I am trying to control her life... She even had the audacity to tell me that I should fucking talk. Oh because I leave some soda cans on my computer desk for a day, yeah I don't leave dead animals to rot and explode while being told every single day to take care of it. She's an adult but acts like a child and I'm so tired of it and all she can do is get wasted and cry about how her life sucks because she's an asst. manager at a store and they don't treat her the way she expects to be treated.

Your parents won't do anything about her behavior?

Not really she's pretty much been able to do whatever she wants since she was 14-15. I on the other hand being two years older than her got to do nothing because they wanted to coddle me for some reason. She's 24 years old now and still is out of control in her life, she had been living on her own with her boyfriend but somehow managed to get herself into debt so she has now moved back in with my parents to hopefully get everything payed off. I've lived with my parents the entire time because I was never allowed to make friends and every job I've held has eventually lead to me having almost serious health problems and I was never able to save any money because my dad pretty much took everything I made, and they wonder why I don't want to get a job right now. My boyfriend currently lives with us and we've been trying to save up for our own place but every time we get a small chunk of money something comes up that wipes everything out. My dad did finally ask her to do something about her fish after I blew up on her, he then proceeded to tell me that my behavior was uncalled for and I should be nicer to my sister...

Wow. I can't imagine having to live with someone like that. What a childish girl. I can't really think of anything you can do to change the mind and ways of someone who is like that. The only thing you can really do I think is what you're doing now - keep trying to save up to move out. Life will eventually teach her to change her ways. It would help if she could get into a rehab program to stop smoking and drinking (and it sounds like some kind of drugs from what I've read) but most of those programs cost money. You might be able to have her go through your state (or province? etc.?) to find some kind of program, but she'd have to be willing to do it. Are you a member of a church/synagogue/etc.? There might be help through one of those places. You might benefit from counseling yourself, although you seem fine to me, I don't know you, and something like that might make you able to see the situation in a different light. I really hope things get better for you, and for your family. I wish I could offer more than words, but I have my own troubles to take care of.