Bad guy train coming through.. choo choooooooo
If you really haven't eaten in 3 days then I think there is a lot more being poorly executed here than meets the eye. A box of pasta and a can of sauce is 2 dollars and would make at least 6 meals.
Does it matter what the 40 bucks is for? Let's just call it 'leisure.' Just to play devil's advocate, how much a week do you spend on feeding your pets? I'd consider pet ownership to be a luxury just the same as feeding the mind for relaxation. Haven't you spent 40 bucks a month on feeding the pets that help you maintain peace of mind and excitement from life? Since the whole 'pot' thing is going to get ripped to shreds...
Alternatively (I have no idea if he even has health insurance) he could get a visit with a psychiatrist for depression/stress, pay a co-pay, spend time he could otherwise spend looking for work dealing with these visits, be required to come back for follow-up (more co-pay), get prescribed a food for the mind that has more inhibiting immediate effects (klonopin, valium, etc) and high chances for chemical dependence, pay more co-pay for the prescription, and still be in exactly the same spot (and potentially having spent more money in the process).
So if it's the idea that he spent it on 'pot' that's turning you away I think you need a new husband (your preference, not his failing).
If he's simply being irresponsible with money in general then shame on him.
If your husband is actually out of work / getting small paychecks then he is definitely due more than 17 dollars in food stamps. When I worked at TJMaxx bringing home 200 dollar a week checks I got over 100 dollars a month in assistance.
Good luck, hope I did not offend too much.
EDIT: 100% agree with BrandiR