Take it from me, Mama, STRESS WILL KILL YOUR SUPPLY! It sounds like you are pushing your emotions to the max, and that will halt your supply. As much as it sounds impossible, you need to relax. I agree with PP, can you get some vacation time? It sounds like you need to just to take a physical and mental time out. That could really do wonders for your supply
When you are with your DS, how many times are you nursing him? Is he nursing during the night?