You seem to be handling all of this pretty well. To me, it looks like he's beginning to see what life without you is really going to be like and based on his reaction to the shirt, he's jealous. That, coupled with the fact that you went out with your girls and stayed out until 2 am, may make him think that there is another man involved in your life now.
Keep GALing and work on improving yourself. He can remain undecided as long as he likes but at the end of this, you'll come out a better and stronger person if you stay focused on yourself. You can't make this decision for him but you can make him see what kind of person you really are and your commitment to your marriage.
