Ok what you need to do is try a new type of med!
As for anxiety coming from depression all I can say is that I have had major depression since I was 12 11 years old
And anxiety since I popped out my mother
Anxiety usually is you think you have something you are not doing or someone is talking about you that sorta thing and the only thing I know that comes out of depression is suicidal thoughts and as for anxiety I don't know I guess.
What you need to do is go to the doctor and tell him how you feel.
Depression is probably the major cause of anxiety, but primary anxiety can also cause depression. One of the reasons anxiety therapy fails so often is the person is more depressed than anxious and therefore lacks the motivations to do what's required to overcome the anxiety. As for overmedication, what are you taking?