Welcome to EmpowHER. Sorry to hear this, I can imagine what you must be feeling. It might be good to talk to your daughter and let her know how you feel about her leaving. Also, while she is gone it might be good for you to seek couseling or psychotherapy. That might help you with the anxiety and depression. And your doctor might suggest Antidepressant medication, which will also help.
I've included some, links I hope they help