The fact that you actually want her back in your life at this point - proves that you could benefit from domestic violence counseling at this point in your life.
You need this not just because of HER - but your non-supportive husband, your mean and spiteful sister, and the absolute lack of support that you do not have around you. I am offering you a number - it's an anonymous number Dot - to the national domestic violence hotline. I get the feeling that you would do very well with someone to actually chat with one on one - and talk to like a real sister who would listen to you and maybe get the nitty gritty by hearing your voice - and be able to offer you some insight - It's 1-800-799-SAFE
KEEP IN MIND - you don't have to be beaten or battered - to call - Just misunderstood, not getting support - verbal, mental abuse counts --and from what you describe with your family? I think you could use a life-line.