One thing it may help to remember is that threatening suicide is one of the manipulations that works the best on women like us. What an amazing amount of power someone can have by threatening to kill themselves!! And if he did, you are NOT responsible. Look at it like this: This man, who has NO PROBLEM packing up and leaving you and your child WHENEVER HE WANTS TO, who has NO PROBLEM leaving you in tears and financial trauma and heartache, is going to kill himself, WHY?? Because he LOVES you?? Doesn't make sense, does it?
At this time, in this place, RIGHT NOW, this is what he will do for the REST OF YOUR LIFE if you continue to be in a relationship with him. Picture that. Can you accept him back in your life, threatening to kill himself, sucking you dry emotionally, leaving and coming back over and over till you are oh, say, 75 or 80 years old?? And do not forget - and this is the biggie, this was hard for me to admit - we become narcissists of a sort, too, when involved with them. We become SO focused on our own pain and survival, and on THEIR stuff (they demand it by their actions), that we often neglect our childrens' mental health. They see mom crying and ineffective, brushing them off because we are blue about our man. What happens to them? My son suffered terribly as a young boy because EVERY BIT OF MY ENERGY BECAME FOCUSED ON MY NARCISSISTIC, ABUSIVE MAN. I cannot tell you what my son did from age 5 till about 8, I was totally submerged in this dick-of-a-man. Is that what you wish for your child?
If this man is a "baby-daddy", as my daughters' narcissitic dad was, then my suggestion (remember, it is a suggestion only) is to have as little contact as possible. If he is not very involved with your child (and my guess is that he is not), get away. Do not make the mistake of trying to persuade someone like that to parent. They cannot do it or if they do, they do not do it well. Get away. Unhook yourself mentally. CHANGE IS AN ACTION, IT IS NOT JUST WORDS. A person who has "seen the light" would not threaten suicide. He would seek help, real help. he would admit he took your money, and try to pay you back, WITHOUT EXPECTING YOU TO GET BACK WITH HIM. He would realize that he is not an effective partner, that he hurt you so bad why would you even want him? And he would take steps to change this FROM THE OUTSIDE. He would not demand BACK IN in order to make it work.
Picture this relationship AS IT IS, because until it changes, really really changes, it is where it is TODAY. Do you have the time and energy to wait and hope it out? Can you afford it? No, I think not.
I am sorry that you are in this position. There is lots of good reading in this forum. There are also interesting articles at drirene.com about Narcissitic Personality Disorder, I think it is in the Abuser section of that website. A man named Sam Varkin(?) wrote a book called Malignant Self Love, about narcissism, and this website posts lots and lots of excerpts. It really has helped me to understand not just what "they" do, but what I do, too.