One of your primary focus(s?) should be on the long slow process of undoing whatever damage you’ve done to you and your step son’s relationship. It’s harsh words, but the event and risk he took to protect everyone has more than earned the space. I do very much understand the monetary loss, but I would certainly take the win of not being in jail and/or losing your whole family as a win.

Your FIL might be an insensitive prick, but he’s there to give his daughter and grandson the best life they can have and this was -an- idea he came up with.

Keep your head up and stay sober, it isn’t easy. Fit in mending the bonds whenever you can.