RT, before trying to go out with her, take some time to sit with your feelings. Focus on the pain and fear beneath the anger. It won't pass until it gets the attention it needs.
After that, try to be grateful that she is being honest with you. Only because it's better than not knowing. You need information in order to make the best choices for you. Take care of you.
Right now she's not in any position to be in an adult R. That's not going to change until she realizes that she has some work to do and decides to do it. You can be kind and loving and even helpful, to a point, but there's no one there to have an R with right now.
Grieve that loss, for now. Things might be different in the future. For right now, think about how you want to deal with the person and situation in front of you.
