Oh, MAN, does this ever sound familiar. A very dear friend of mine when through exactly - and I mean EXACTLY - the same thing. He was out of work for 18 months at one point, had nearly 60 interviews in that time. The words he heard most often were, "You're overqualified." As well, he knows for a fact (so he says) that he was turned down for positions because he happens to be a middle-aged white male in an era of "employment equity."
Eventually he got 2 job offers, both short-term contract positions. Neither of those positions developed into a permanent gig, one because the company declared bankruptcy and the other because of a massive layoff sweep manufactured by the company to satisfy a short-term blip in stock price.
He continues to struggle, though he's finally scored a full-time gig.
Point is that this sort of thing happens all the time. By no means are you alone in your situation, it's extremely common.
There is, alas, no magic bullet that I'm aware of other than the usual exortations to keep focused on your goal, you'll attract what you think of, etc. etc. And keep moving forward. Stay focused and keep taking action.
I know it's hard and that the shadows of negativity are hard to illuminate. But you will get through this.