OP, I'm just wondering - is this a friendship you have had for years, possibly from school?
Has your "friend" now got a new set of friends? If so, it sounds to me that they are now her priority and she would rather be spending her hen do with them than you, but because you have been friends for so long and it is convenient for her she is keeping you involved in her wedding arrangements. She can obviously rely on you to fulfil all these jobs she wants you to do and she doesn't want to put pressure on her other friends.
I don't think she has any respect for you and I feel that once the wedding has taken place and you have helped the day run smoothly she is probably going to drop you.
At this point, I think you very much have to decide what is going to work for you:
Do you want to grit your teeth and fulfil your duties because you have been friends, it's her wedding and would you feel terrible causing her an upset so near to her big day?
Or, do you want to explain to her that you feel hurt and miffed at what she has done and because of those reasons you are going to step back from your role on the day and let one of her other friends step up?
She is not respecting you. She is not thinking about your feelings at all, she is more interested in her other friends. I'm sorry to say but it sounds like she doesn't want you at her hen do but she does want to use you to do all the jobs she wants done.
Whatever you decide, hold your head up high and if you go along with her wishes and do these jobs, after the wedding distance yourself and if she contacts you, explain about the hen do, explain that your didn't want to cause her any upset or stress so you fulfilled your role on her wedding day but that what she did was very hurtful.
If you don't want to continue, tell her soon so she can get someone else to do these jobs and don't let her emotionally blackmail you into doing something you don't want to.