Are you looking for another job? Sounds like you need to start getting the resume out there and starting your search for greener (or at least friendlier) pastures.
If quitting's not an option: are you willing to talk to HR to discuss what you've been going through lately? I'd recommend bringing along a note from your doctor about how your condition makes you behave under the pressure you deal with so they can understand things better, and hopefully lighten your workload rather than firing you.
If you're with a bigger company, you may check into their Employee Assistance Program (EAP). Most have counselors available 24/7 to confidentially talk about problems with employees.
Short of any of that, yes - see a therapist in person, and don't be afraid to lean on friends and family to get you through this. That's what they're there for. And that's what we're here for. Please keep us up to date on how you're doing, and the best of luck to you as you get through this.