I also wanted to add that it is a real slap in the face when reality sets in. Feel what you need to feel. Grieving is an essential part of this process and IMO a very necessary one.
It is okay to miss your H and the family life the two of you once shared. You are a human being, not a robot!
You are NOT helpless though. You are helping yourself therefore you may *feel* helpless but you certainly are not. It is very important you remember that.
In one month you have adjusted to being a single parent with flying colors, took proactive steps to increase your income, began socially networking to help rediscover business contacts and help yourself GAL as an ADULT (not a mom or wife), have been paramount in the diagnosis for your son AND realized where you need to focus your attention (setting boundaries, detaching and all that good stuff). Not bad for a mere 5 weeks!