How to avoid confrontation in my house?

I'm glad you're planning to go to college. You write very well. You might consider studying psychology.

Your mother doesn't want to parent, apparently. That's sad. I'm sorry that speaking with her hasn't done anything.

There are a lot of things you can do.

1. If you're in America, contact Nami.org. They'll set you up with a peer counselor, someone who can help you (for free) understand the dynamics in your family. It will be someone who also have a schizophrenic or bipolar family member.
2. If you can't get help from NAMI, try calling United Way and asking what agencies locally can help you.
3. Talk to your local Rotary Club about going away to high school in another country for a year. That will get you out of your home and living with other families. You'll need to know another language: I see from your other questions that you know Spanish, so you can go to any Spanish-speaking country. It will really help you improve your Spanish, too. In a few months, you'll even be dreaming in Spanish!
4. Look into fulfilling your high school requirements and going to college early. I did. It's a tremendous relief to know you can get out a whole year early. Look into going to a dorm school. Ask your mother what she thinks she can put towards college. Does she have savings for it? You need to know so you can make plans for where to apply and what you can afford. It will be a conversation you can have that isn't about your sisters. But even if she can't afford it, you can go on scholarships, loans and grants. You can talk to your high school advisor about it and start researching it now.
5. Figure out when your bossy sister is the worst and find a way to get out of the house at that time. Is she terrible first thing in the morning? Join the swim team so you're already at the pool when she's in a bad mood. Are evenings worse? Join theatre so that you have late-night rehearsals. Is afternoon the worst? Join an athletic team or band or choir or the school newspaper. And since it's summer, you can take up running right now. It's a good way to exercise and it will help you blow off steam, and you can do it anywhere at any time. So when she's being terrible to you, you say "Hey, time to get my run in" and you take off and go. I see from your other questions that you're overweight -- this will help, and you can start with walking and then go to jogging every other minute and work your way up to running. Oh, and you can always go to the library. And get involved in a house of worship. Doesn't matter what religion or whether you believe in religion. They all have a youth group, and it gets you out of the house. You can join a Boys & Girls Club, too, and that has programs that get you away. Or you can join Scouts and go camping and also get other adults involved in your life.
6. Consider getting other people to be your witnesses, particularly adults. Does your mother have any friends? Do they see what's going on? Can you ask them to talk to her? If not, can you invite your friends' parents over? If you can get others to see what's going on, the adults may talk to your mother about what is going on. You can also try talking to your friend's parents about your frustrations and see if they have advice. Also, if other people are at your house, particularly adults, your family may be on their best behavior so that others don't criticize or gossip about them. You can also go to other people's homes, and that gets you out of yours.
7. Can you get a job? It doesn't matter what: babysitting, being a nanny, doing laundry, mowing lawns. It gets you out of the house and gives you money that you can spend towards your dreams, like going to college.
8. Find a book called "The Normal One" and read it. It's about having a sibling with something wrong, and I think there's a chapter with a schizophrenic sibling. That might give you some insight into the dynamics of your family.
9. Ultimately, is there a family member where you can stay? You don't mention a father -- is he involved? If not, is his family around? What about grandparents, or aunts and uncles?
10. Try to understand that your bossy sister has a very small, pressured life. She's in your life because she doesn't have one of her own.

Good luck to you. I'm sorry you have to go through this.

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