My friend asked me to be her maid of honor. I think I'm just going to block her.
That is not a nice thing to do, why would you upset her like that?
I hate listening to her problems and helping her with her drama
I can understand your feelings, you should be there to support your friends when they need you. That is what being a good friend is for. You should take time out and think about what this means to her.
She's a strong person and can deal with it. I don't think she needs my help.
Sometime just telling someone that they're strong enough to handle something is enough and you legitimately feel that way. Blocking her would be cruel as she just gave you an important role in her wedding. Just try to look at things from her perspective and you'll see that she really wants you to be there for her.