I'm on the other side of the desk. The more accurate financial information you can provide, the better and cheaper representation you'll get. Also tell the lawyer about possible hidden assets. You should explain WH is /was in an affair and who the OW is vis a vis employment. IF WH is anxious to divorce due to pressure from OW, you are in a much better negotiation position.
Ask the lawyer for a timeline, too. You should know about how long a simple, uncontested divorce takes and how long War of the Roses II takes.
Understand, lawyer isn't psychic, cannot know how contested this will be, and therefore cannot tell you any exact fees.
With the medical news, you should look into insurance coverage for spouses versus COBRA for former spouses and what costs are. Make sure you tell lawyer about this concern.
If the medical news is bad news, don't divorce. Happened to me once--my client died before final divorce judgment and W got everything. Adult kids weren't happy, but W ended up far better off. Yeah, I know that sounds crass, but it is true.