I have nothing wise to add to the raft of suggestions you've already received, not to mention the endless avenues you have already negotiated. Perhaps you may consider a two week trial of melatonin for O if you haven't already done so.
Laura, isn't it absurd how bad is never good until it is worse? But what's also ridiculous is that love knows no limits to it's endurance, no fading of it's hope, and storms certainly do make trees take deeper roots. Anyone can give up, it's the easiest thing in the world to do. But to hold it together when everyone else would understand if you fell apart, that's true strength. I don't assume to know you well enough, but from my POV I notice someone with tremendous courage, tenacity, and lion-heartedness. Thus I applaud you for not only having the strength to traverse your own situation (and what a situation that is too!), but also extending a helping hand to those who require it.
One day your son will understand and know who you are; his mother, Laura - the gallant Lioness.