The bond is sometimes much stronger between human and pet. That's because pets tend to give unconditional love and don't judge. Think about it... you can be who you are and say what you want without any fear or consequences.
It is possible that he's getting stressed because you have been under a lot of stress lately. The bond goes both ways, you know.
Loss is very difficult to deal with in any situation. And it affects each person differently. To have so much happening at the same time is nothing short of brutal.
Perhaps it would be beneficial for both of you if your doctor could prescribe something that could help calm your anxiety?