It sounds to me like he's "punishing you" for not working. He resents you not bringing in an income, or not contributing your fair share. No wonder it feels abusive to you. It is.
Do you have any access to money at all? Do you have a debit card? Can you withdraw cash?
Are you both signed up on the account? Does your bank have online banking? If so, sign up. If not, go to the bank and request a bank statement. Withdraw some cash for you, or open a savings account for yourself and transfer money into it. You need a safety net. Check out the bank transactions on your joint account, and see if something is fishy.
Quite honestly, I didn't think of cheating when I read your post. It certainly is a possiblity, and one worth considering. However, the feeling I got was that he was hiding something. Whether it's gambling problem, or a drug problem, or he's working fewer hours and bringing home less cash, or he lost his job and can't tell you... Something like that. Or it could just be how he expresses his anger toward you, because you are not contributing financially to the marriage. (Yikes)
Remember that even though you may not be putting a paycheck into your account, that doesn't mean you aren't contributing to the marriage. You are a stay at home mother, which is a HUGE contribution. One that is an investment in your son's future, and very valuable indeed. You also contribute in other ways. Consider how much your husband would pay if he had to pay a cleaning lady, a cook, a nanny, someone to do his laundry, etc. Just because he gets compensated with money, and you don't, that doesn't make your contributions less valuable.
Are you no longer allowed to spend money at all?
If he's paying all the bills, does that mean you are allowed no access to money for any reason? Is he going to buy your tampons for you, give you cash to go to the hair salon, buy your makeup, give you gas money? Will he be the one to give your son money for the father's day project in preschool? Or the field trip in kindergarten? Will he give you toll money so you can drive to your friend's house, or your mother's house, or to go to that job interview? Is he buying his own Christmas present? How are you supposed to function in these circumstances? He's not just taking control of the checkbook here. He's taking control of the entire family structure, and effectively putting you in your place. A very low place.
If he felt that money was an issue, and you needed to bring home an income, he should have been able to discuss this with you. Not punish you by taking away your access to money and criticizing how you have spent it in the past.
What's odd is that you say that he makes enough money. And you should know, since you formerly controlled the finances. Why does he now turn it around and say that you didn't handle it correctly, or that needs to take control? Or act like money is really tight? Why is he doing this? Is it control? Punishment? Or is he trying to keep you from seeing something? None of this is good.
You really need to revisit the need for counseling. If he won't go, then YOU go alone. NOW.
Can this be worked out? Sure it can, if he is willing to talk to you, share his concerns (not blame), and work together toward a solution and a better future. But it sounds like you've tried this, and have had no results. You have even tried marriage counseling.
(Perhaps instead of a marriage couselor, you should be discussing these matters with a lawyer.)
Good luck. I hope you are able to get through to him, and that you two can resolve this issue. It can't continue the way it is.