How can I stop feeling so overwhelmed?

I work 9am to 11p Mon - Fri and 5 hour shift on Sat(50 hrs a week), with about 4 hours in between during the week to commute, clean, cook, raise 2 teens etc. Husband has same job but lower pay and hours than 2 yrs ago. Doesn't want to get new job, extra job, side job (says knows he needs to, but hasn't).

Struggling to keep up with bills, always getting disconnection notices. Car keeps breaking down (I've had to take a bus, walk for groceries, beg for rides etc). Kids don't want to go to school, oldest struggling with anxiety and depression, can't bring himself to talk to potential employer, he's almost 19 (refuses therapy, has had about 12 yrs of it since age 5).

Husband also won't help around house and then its minimal when I insist and not without argument, gives allowance to kids when i tell him not to because they didn't go to school or do chores, he won't fix drafty doors and windows that are literally falling off the frame and give receipt to landlord in lieu of rent, landlord won't fix (allows us to pay rent throughout the month, can't take rent to courts and demand fixing).

I have an older sister who argues with me that I should let her binge drink at my house, tell my son he's like her and will always struggle with life (stupid hoe!..sorry it infuriates me) and then tells me that it's not a reason for her not to drink here, she's an adult and my kids hate me anyways. She even talks to and meets...yes, meets random guys off of craigslist!..from my house! I've kicked her out and she keeps coming back and trying to bribe me to let her drink.

This is just a brief synopsis of my situation, I haven't even started talking about my alopecia, arthritis or hypothyroidism. My daughter had her appendix out 3 months ago and now has severe pains in her stomach we're trying to figure out , she has laser surgery continuing for a facial birthmark and plastic surgery in the near future.

All these things individually, not so bad, but all together are just killing me. I can't think straight, I'm starting to feel tightness in my back and neck (trying some yoga stretches) and sitting all the time for work doesn't help, but I think it's mostly stress. I can't seem to financially get it together to leave my husband, can't find it in me to kick my sister to the curb for good until she stops drinking here. I have no one to ask for help, the rest of my family will probably say its all my fault and just tell my I need to figure it out. So I'm looking to strangers for help...I think its my best bet right now. Thanks.