hallelua,
well, first of all, WELCOME to sober recovery. i hope you find in this forum the support you need and seek. many, many of us have had similar experiences, and to make sense of it is....well, pretty tough, if not impossible.
please post here as often as you like. it can be very helpful.
as for all the questions and anger toward your husband:
1. you have every right to feel abandoned, and angry.
2. you may never get all the answers , but you gain perspective after some of the dust settles.
my opinion, based on being married to an alcoholic man, is that they simply are not truthful. oh it's not always malicious, or intentional even. but i believe it is a disease rooted in dishonesty. because, you see, if they were able to be fully honest, then they would know, and admit, their problems. whatever discomfort or fear has caused him to leave, and there could be a hundred, probably doesn't even matter.
what does matter, is that you are able to pick up the pieces, and go and create a better life for yourself.