I think the daycare argument going back and forth here is very black and white. Here is a useful website about daycares, that seems to be reprsentative of either side.
http://www.saferchild.org/daycarefaq.htm
Not everyone has the option or constitution to be a stay-at-home parent. But experts say - and Safer Child tends to agree - that staying at home for some or all of the first three years is generally better for the child. No matter how lousy a parent you feel you are, your child has a powerful and innate longing to be with you and to know that you want to be with him or her.
Personally, I think you have the option to be spending more time with your child, but you are playing poker instead. It seems that your priorities are a bit messed up. The good thing about playing poker for a living is the flexibility. There is no reason you can't have your kid at home, find a pre-school or similar environment to put him in a couple times of week, for a few hours, and get your poker in then, or while he's sleeping, etc etc. Plus, if you're playing 8 hours a day of 10/20, you should be making waaay more than 20k a year.
Also, I wouldn't be surprised if your husband resents the situations. Your a stay at home Mom, but skipping out the "Mom" part.