I've got to admit there have been many moments that I have shared the exact sentiments you have expressed here. Typically those feelings come on my "down" days, but in truth, they are always there. I have benefited from this site very much, but I've also learned some hard lessons and, like you, found that the pain I've experienced (from my affair and my H's 2), and the pain I've witnessed in others, leaves me feeling a bit less hopeful than I'd like to be.
Sharing your pain,