Crimson, Monday will surely not be your easiest day, but given your W's texting you about the letter she was composing, it will probably (not trying to mindread, here) not be easy for her, either. It could be that the actual mediation session will make her think again about pursuing the D further; it's not uncommon for (non-D) cases to settle out of court, no matter how contentious they have been, when it gets down to picking a jury.
Also, if it's just an initial settlement conference, it sounds like nothing has to be finalized Monday. As Rick said, you'll survive. Hopefully you can take some time to treat yourself and GAL this weekend so you'll be the best you you can be under the circumstances on Monday. Good luck.
