My life's falling apart because of my anxiety, anyone have advice?

I've had anxiety on and off for years now but im currently in a hugh slump which i can't seem to get out of. I get this feeling of detachment, it's so hard to describe the way my anxiety makes me feel but i get so detached from reality that it causes almost a dream like feeling that combines with the anxious and panic feelings. These feeling drive me crazy and make me feel like im losing my mind. I always try to push myself to go to the gym and get my homework done but my anxiety fights me every step of the way. I can be extremely motivated one minute and as soon as I try to act on something that would be productive my anxiety kicks in and makes it impossible. I'm so frustrated, I can't do anything anymore. I'm falling so far behind in school and im getting so out of shape, my anxiety is ruining my life. Also I've tried making an appointment with a psychiatrist but every one I could find is booked for at least 2 months. I try to exercise as much as possible and do as many productive things each day as possible to make myself feel better but my anxiety makes it so hard to get anything done. Any advice would be appreciated especially from someone who has been through this. Thanks so much