LT, you are certainly dealing with alot and the pain, frustration, confusion, etc.... you seem to be feeling is all perfectly understandable. Thoughts and prayers are with you!
Not a ton of advice, certainly not expert in depression and your W has taken some pretty drastic steps that I am only a little familiar with.
In terms of the proposed letter to FIL couple of thoughts - it seems a bit long and I am not sure that he will "hear" what you are trying to convey in the first section of the letter given how he has been described and where things are currently at. There may be a time later for this - just my thoughts....
What about expressing confidence that you are aware that everyone wants the best for all parties involved and then move on to what you feel the girls need right now and what you will be encouraging them to do (points 1 &2 above)?
The rest may be better served for another time and place - just my opinion though and certainly understand that you are in a unique and challenging position.
Stay strong!
Me-48,W-51 M-22,T-24 S- 18,16,9 Feb-Jul '11 Away from Home, after initial B date Aug-Dec '11 Back at Home on couch Dec '11-now Same bedroom, room mates only Dec '14 W files initial D paperwork
