Don't worry about the divorce - the military will make sure that your child support comes straight out of his paycheck. Ask for the maximum support and alimony and take care of yourself and your boy, and move on.
As for your son, don't lie to him, but don't ever talk his father down in front of him or to others where he might possibly overhear you. He'll know, and it'll turn him against you. I know, because my daughter's father and his family tried that tactic against me, and I always stayed positive about him despite the fact that there was plenty that I could have said against him, but it would have been hurtful to her to say those things about someone she loved. Your boy has a right to look up to his father, whether the man makes any actual effort to have a relationship with his son or not. Don't allow anyone else to poison the well, either. Demand that anyone else in your son's life (grandparents, new men, etc.) speak respectfully, or at least neutrally, as well.
In time, your son will make his own investigations of and judgments about his father. He'll respect you even more for letting him do so.
Learn to stand on your own for a while. It'll be healthy for you, and good for your son to see you do it. After you prove to yourself that you can take good care of you and your son for at least a year or two, you'll be more confident when you do give yourself permission to start dating, and you'll have higher standards. Go really slowly when you do start considering the field. Don't go out with the first guys who express interest. Take it slowly, and find men who are stable, strong, and good with children, men who have already proven that they can and will stick around and take care of their responsibilities (kids, parents, whatever). Men who have stable jobs, no drug or alcohol problems, no criminal histories, etc. You don't need to be in a hurry, because this isn't a race to be run.
Good luck!
