This is the same girl that posted that her brother threatened her and stole her passwords on the computer. And that when she told her pediatrician the parents got mad. This family has some deep issues and NEEDS help! Young lady, if everything you are saying is true, you need to talk to a counselor at school, a teacher, someone who will believe you and intervene on your behalf. Your parents need to be contacted by child protective services. I found myself wondering if you are Amish or from another country ro something. I fear for you.
It sounds like your parents could use some help, in relation to both thier individual issues and their marriage. In addition, they would benefit from some guidance re: parenting issues. Who can intervene with them on your behalf? Is there someone at your school (teacher, guidance personnel) who might be helpful? Is there a family friend or acquaintance who might speak with them? I'm sure that your parents want what is best for you, but they may be confused or misinformed about how best to interact with a teenager.