rysmom, please don't see the 2x4's coming your way as people being 'mean' to you. These are folks who know and care about what you're going through and are trying to help you find your way.
Use those 2x4's to build a strong foundation for you and your son to see you through this storm.
What you did the last time with your H didn't work out so well or he wouldn't have left again. Obviously issues were not dealt with and if you're honest probably got swept under the rug.
It's time to try something different. This time focus on you and your son. Give your H time to miss you and find out what life is like without rysmom in it. It's human nature to want what you can't have so turn the table on your H. Work on yourself, heal and become whole in your own right. Forget about H and what he's doing right now. This is your time. This will prepare you for your H's return or if he doesn't it will give you the knowledge and the strength to have a fulfilling life without him.