9, i cant comment on the medical aspect. i just wish you the best of patience.
OW must be talked to. be kind, explain and ask her to understand. who knows what the future may bring. although having someone to confide in while going through this may be good for you.
your kids will need to be talked to also, they'll be exited W is coming home (?) but need to understand this is the beginning of a long, hard process. The outcome is still very unknown.
you'll have to detach yourself like you've never done before. the less emotion you have, the better chance for everyone.
my xBIL was diagnosed as bi-polar. and it was not pretty. and while his current medication is working, it took a long time for them to get it right.
learn about bi-polar, go with W to doctors and talk to them, etc.
but most of all detach and go slow.
"In a ham and eggs breakfast, the hen is involved, but the pig is committed".