I don't know the history of issues between you and your daughter, but I wouldn't necessarily blame her behaviors on a problematic relationship. Does she have anxiety? Behaviors anxiety cause can be severe. Are you her "safe" person she takes things out on because she feels most comfortable with You? If so, that's good. She just needs to work on how she handles herself. Don't accept her abusive behavior. Making it clear that her disruptive behavior in the home will no longer be tolerated can be a good first step.
That said, her moving out is going to be the best thing for everyone in the house, especially her. She will never learn and grow to her full potential until she is out on her own, making mistakes and learning from them, and taking personal responsibility when necessary. Allowing her stay at home is preventing this and it is enabling her. I like what you said above. Let her know you want to help the relationship, and a little space may be just the thing which is needed for her/everyone. And yes, let her know she can call or text anytime, you love her, etc. If you get inundated, you don't have to answer every call or respond to every text, and certainly not in her timing.