I don't know if this is helpful, but both you and your sister should have long since moved out of your parents' house! Both your parents are very toxic people who have damaged both you and your sister.
You really need to get some good counseling not only to deal with the abuse but to also find out why you can't keep a job. When you get counseling, you can also find out if you have a mental disability that keeps you from holding a job for long. If that is the case, then you can apply for disability payments. At least that will get you out of your parents' house.
There are sexual abuse hotlines you can call to get started on this. I don't know if you are in the US or not so I can't pass along any phone numbers. However, with a google search, you can find a hotline.
Good luck and get going! It is long past time for you and your sister to be independent and out on your own!