First of all icerain well done on raising your sister, you sound like you were a fantastic parent (I know you said sibling !) and did all you could to help her in times of hardship. As Sandra said maybe she does view you as the parent and is finding her way in the world and this is not your fault or hers, its needs to be done in order for her to mature and learn not everything will fall into her lap as you did for her . Take stock of your life and get out there and start meeting new people, take up a course, travel, party do something that you have always wanted to do, a bit of "me" time keeping in mind you have done all you can for her and now she is on her own two feet
