I have read your sitch and what seems to happen with most situations on here is there are almost cycles... The bi-polar probably doesn't help in your case.
My wife at the moment seems to go hot and cold all the time. Although currently it is a warm phase. Remember that they are going through the stage of "Is the grass really greener?", and unfortunatly there is nothing we can do to change their mind.
My wife even said to me last night that if we tried again she would feel like she would lose her freedom, to which i responded she would still be able to do what she wants to a certain extent while we worked on the marriage but we were to be faithful during that time.
I only mentioned that because quite often they drop the bomb, then really enjoy the first few weeks or period thinking that it feels so good to not have responsibility to another person, even the kids get affected.
The problem is also, sometimes by the time they have figured oiut a big mistake has been made. We will have moved on because of the pain this person causes you during the whole seperation.
I don't know if this helps much, but I seem to see so many similar patterns in alot of the Walk away Spouse posts.
Take care of yourself and Daughter, and I hope he eventaully sees the way. Also, is there anyone that you know as impartial who could possibly talk to him regarding his bi-polar and getting treatment? Surely some of his friends would know the situation? Obviously you wouldm't want him knowing that you put someone upto it. BUt if you had ssomeone you could trust bring it up... I think that is your biggest obsticle - the depression and bi-polar.
Good luck.
M - 30 WAW - 29 D - 8 S - 5 BOMB - 09/12/09
My Situation - http://www.divorcebusting.com/forums/ubbthreads.php?ubb=showflat&Number=1842559#Post1842559