I know it's not going to help you much if I say that I am your friend and will be forever, cheesy as it sounds, but here's a few ideas.....
At your school, talk to someone about your aunt. Both her, and your cousin need help. maybe not your cousin, but I think it would be pretty alarming to see your own mother attempt suicide.
You also need to talk to someone about you. Show them this, and tell them that you really need help. You sound like you could be suicide quite soon, no offense.
Don't worry, everyone has rough patches, they are depressing, but eventually they go. Mine was, (maybe not so severe) when I was 10.
For a while I watched my mom get totally stressed, there was a recession, we didn't know what would happen, and we ended up moving from the place I grew up in and loved to the other end of the world, it wasn't like moving from London to Canada
I moved from an amazing Hong Kong to a place I hated, Dubai. I had no friends, I was in a strange place I had never been to, instead of the usual Chinese signs (I was used to them) and occasional pagoda, there were signs in arabic and huge isolated mansions everywhere.
Eventually I made new friends, got a new life, and 3 years later I loved it and didn't want to leave.
I know your situation is different, but talk to someone you trust. Maybe your mom's doctor? or a teacher who you know? ( I know, I don't think teachers are easy to trust, but just try, you might be surprised. )
I really hope you do better, you can email me if you want,
your friend forever,
Hope that helps!