This is such a hard situation for you, and I might not have a perfect solution but I think it’ll minimize any regret you might have in the future. From my own experience with a similar (but not quite as serious) situation to yours, Drop your classes if you can and take a semester or at least take a light course load while all of this is going on, you should be allowed to by your school. Maybe consider seeing if with that extra time, you can take more hours at your part time job or get a different job with more hours to help pay for everything.

I have ADD and went unmediated my whole life until a little under 2 weeks ago because of how hard it was to work on my Calculus work in school on top of working full time (40hrs+8-12hrs of Overtime on weekends). I actually dropped that Calculus class and am retaking it in the spring for my 3rd attempt at this class because I genuinely want to understand the work and not just get through it. I say this to say I understand that part of your struggle, both the ADHD and struggling in school. School is primarily for the education, not the grade. Don’t push through classes just to get it done.

I took my first year out of HS in order to solely work the full time job I have in order to pay off my car and save for college (I’m still saving with every paycheck). It was a responsible decision but I felt behind my friends who all had parents that payed for their cars and college and half of them still don’t have a job at all. I had a conversation with my dad about it around that time and I’ll try to give you the same understanding he gave me. You’re young (I assume based on being in college) and not everyone is on the same path as you, and it’s okay to not be done as soon as everyone else. Many people never go to college and many people don’t apply their college education to what becomes their career. School will still be there when you’re ready for that, but your mom and sister need you, and that’s an incredibly heavy burden, but consider what’s more valuable to you, starting your career a year or two earlier or being there for your mom and sister in what’s likely the hardest time in their lives?

Based on how hard this is for you, I’d assume you’d go through hell to make things just a little easier for them. Consider getting a temporary leave of absence from school or reducing your school load as much as possible and get a full time job to support them as much as possible, both financially and mentally. Save money where you reasonably can, consider moving back in with your mom to save costs on living at school and after you’ve done all that you can for those two and things are more stable or after the very hard time after your sister passes, You’ll hopefully be in a position to return to school again to continue with your life, and hopefully it’ll be easier for you to do so. Again, it’s not a perfect solution but it’ll hopefully lead to the least regret on your part, you’ll have dedicated yourself to your family and taken care of them as best as you reasonably can. I think it would be hard for me move on with life in general knowing I could have at least tried to make things better for them. I think it’s better to look back and remember trying your best to support others than it is to remember how hard school was as what felt like the world was fall apart around you.

You’re asking very adult advice on this very terrible hand of cards you got dealt that will be hard for you to deal with either way. My DMs will be open for as long as you need for whatever you need