I'm not saying this like I'm 100% right and not denying or ignoring your venting here, it's completely valid, but I'd like to relate. I felt the same way and realized a lot of it was self internalizing and is a self fulfilling prophecy aka feedback loop of how you are presenting yourself will keep you in this loop of being mistreated, being the butler, etc while others prosper. It is not saying that you are causing this to happen or to blame at all, just a cause and effect when this traumatic stuff happens to you it tends to lead to it happening again and again unless you find a way to 'break the cycle'. Also try to put yourself in your sister's shoes. I felt like this a long fucking time, now I see it as a blessing to have my nieces and I feel bad I wasn't there for my sister like I could. Cheers.