I can relate to you, I think a lot of others here will too. I've felt exactly the same over the years and turned down countless bookings for no reason at all, my advice is get back into bookings gradually, accept shorter bookings and you'll hopefully have some good clients that will motivate you for the job again, this is what I do when I feel like you and it always works for me.
As for nasty comments on forums! It's easy to say ignore them etc but it really is short lived in the grand scheme of things, don't read them and make yourself look amazing, get out of your pyjamas and dress to kill girl! Even if you go down the shops you'll feel better!
Hope that helps xxxxxxxxxxxxx