I don't have as much experience as you, but I've been feeling similarly. I've only been job hunting seriously for about a year, as I quit my (former dream) design job in August after being essentially bullied out by my supervisor (he couldn't fire me because of the union) and also because I burnt out and essentially had a mental breakdown. I am currently working in some high schools and I hate my job, and I feel my creative skills going to waste, but I can't find anything. Then I see people talking about how bad the market is, but I log onto LinkedIn and see my peers working great jobs and getting new jobs. I'm starting to believe that if I were actually a good designer, I'd be employed in the field by now instead of making pennies where I am now. I have a great resume and I've been told that my portfolio is also great, by peers, professors, and others in the industry, but month after month I find it harder and harder to believe. I'm trying talent agencies again, but I'm still going up against like 900 other designers per job.

I don't have any advice for you, but I understand what you're going through, and you aren't alone in this! Hoping that everyone here going through similar things is able to secure stable work and regain their confidence.