Reading your post brought me back to the insanity of when I was at my sickest...I could picture myself looking up cell phone records, making phone calls all over, arguing, pacing...and it made me feel really stressed. I imagine you are stressed too - I'm sorry you are going through that. Perhaps you can ask yourself whether your goal is to make sure you do not lose out financially by trying to control his actions and get him to court in a couple of months or to restore yourself to some level of peace...or maybe it is something else completely. If you are primarily concerned about the finances, you may face some stressful and strained days for awhile...and no matter what you do, you may not be able to control what he will do come time for court.
I think in your shoes, I would try to choose as Freedom said - trust in a power greater than me; focus on myself and let things unfold.