I feel at the lowest I’ve ever been

Recently my sister had twins and I have been helping her with literally everything. I went to the hospital with her every day when they were in the incubator and since they live with us, I’m always with them. When they were born I had recently quit my job for unrelated reasons and my parents told me to not get a job so I can help. At first I agreed because I thought her bf was going to be more present but he’s not. He only sees them like 2 times a week and only for a couple hours until he gets annoyed and leaves. I have put my life at pause to be their “mom” and i hate it. I missed the deadline for college and I haven’t been able to get a job. I have lost weight because I eat once a day since I don’t have time. And I never go out. It’s hard to connect with the few friends I have since I never know if I’m going to be available. I feel so alone and lately really depressed. I hate that my sister thinks I can just stay at home and do her job. I get that she has to work but it’s not my responsibility. Every day i wake up with dread and not wanting to be here anymore. I hate how my life is now. I feel so burnt out and tired. I feel guilty when I don't get up at night to feed them but I'm so tired. Mainly of how repetitive it is and how this is now expected of me. Everyday I reach out to a suicide hotline because I feel so defeated. I get anxiety and panic attacks now. I’m really struggling mentally and don’t know what to do.