Do you think it would be horrible to tell my girlfriend that she's not special because she's going through some shit
Is that what you would do to a different person if you found out they're going through a hard time?
I'd tell them that special things happen to special people.
Even though you might be frustrated at your partner for her behavior, you should understand that she is going through a difficult time and needs support and understanding from you and not being admonished for her behavior. In order to be a good partner, you should be there for your girlfriend or otherwise your relationship will suffer and your girlfriend may think that you do not love her. Try to best accommodate your girlfriend's needs while she is experiencing a difficult time.
I don't give a fuck, she has to suffer.
You should probably reevaluate your commitment to your relationship. If you don't want to support her when she's struggling, then you probably don't really want to be in the relationship. It might be best to move on, so she can find a loving partner.