megamania, I don't know too well, even from these boards, but I just want you to know that I hope you are doing alright. I'm only 18, but I had a girlfriend of two years who I recently split with, and that hurts very keenly still - so I know, to a point, where you are coming from.
Your life sounds extremely chaotic at the moment, so I'll echo the others in this thread and say that you need to sit down and have a breather. Anything you can do to relax and take the stress off your back - even go for a massage, or something like that.
It's good that you three sat down, as adults, and discussed the situation at hand; it's also more than a little fitting that he is now worried if the cheater he won will cheat on him ("aye, there's the rub"

). Such is life, eh?
Likely you will end up having a few more meetings like that, which is good - so long as you are all being mature and it doesn't break down. The less you need to get a lawyer to jump in, the better for all - especially since your financial situation is not stable right now, and lawyers can be pricey :\
I will again echo others in this thread that you need to worry about yourself first off right now. I can't even stress that enough here. Do what you need to do to get yourself comfortable - you need a house? Go house searching. At this point having a stable base of operations is more important than the distance between you and your children - remember that they will love you no matter what. I was abused by my father physically and emotionally as a child, but even I could begrudgingly admit to loving him now (well, not to him, but you get the point); even after living out of his house for more than two years. Anyways, piont is that they will be there waiting for you, and the faster you can get yourself settled, the better.
Also, don't worry about snagging a new woman yet - your life needs to be more stable first, and you need a house mroe than you need a woman, even if the woman comes with a house

Point is, you have too many wounds right now, and that will only add more obligations in your life. Also, you children are already seeing their paretns split up, and are already probably very confused and unsure of the future, and you don't need another new face to add to the hysteria which has landed at your feet. My father started dating only a few months after my mother passed away (and indeed there are rumours of him starting this relationship even while she was in her last weeks) and I personally wasn't impressed with it. This is not to say that new woman you choose will be a bad choice, ot a bad person, or whatever; but you need to look after yourslef first, get adjusted to the new situation, and then you can go hunting for a new lady for your life.
As for the attempted suicide, know that it isn't worth it. I've been at odds with my own mortality more than once, and everytime I shy away from that bottomless pit. Dead is dead, and you will not be helping yourself or your children if you do something like that. Suicide isn't thoughtless - rather it's usually well thought out - but it can be impulsive. Watch your own back, and know if you are straingin yourself too much. Also, talk with someone you trust who you know will be unbiased, but empathetic to your problem/crisis.
I don't know if I could or can say much more to give you hope other than to say that that I hope that this will all end up in a satisfactory way. The best quote for this situation: "Hope for the best, prepare for the worse." Always make sure to watch
your back first, best of luck in the coming trials and remember that everyone makes mistakes, and forgiveness is divine
Peace, Nyaricus