"I think I can get over the betrayal by Bob, I just wonder if these feelings for Jay will ever go away."
Oh, I don't suppose they ever will. They'll probably "simmer down" and "sting less" after (quite) awhile, but you'll probably always have a certain emptiness in your heart where Jay used to be. Relationships that strong don't just go away; they always leave an echo.
I think you're upholding as good and positive an attitude as anyone could be expected to under your circumstances. Sorry to hear about your job situation; you certainly don't need that extra stress.
Jay sounds like a scared/wounded man. I suppose I should be saying that about Bob, as the tantrums reveal Bob's inner insecurity, but Jay paints a picture of fear and trembling. It'll probably be better for him if Bob does (someday) leave him for someone else, but it's not my place to judge how difficult it is to be in Jay's shoes.
I hope you find some healing and relief in the months ahead.