Well, I didn't know you that well, but as someone who was extremely depressed a few years ago (for about two years) I say: take a break, and find a good therapist. You don't have to go forever, you could come back. leaving for a week, a month a year, or several years is better then leaving indefinitely.
If you do leave I shall miss your work, even though you have not made any comics in the last few weeks. (or months? )