Why would claiming married with 2 dependents vs single, head of household claiming none cause my estimated taxes in Quickbooks Self-Employed to increase?

So last year I got married and after doing my taxes (married filing jointly) I ultimately ended up paying the government too much money therefore I am getting a return.  In order to adjust for this for this year I adjusted my tax profile to reflect married, filing jointly, added my spouses income (W-2) and claiming two dependents which I thought would cause Quickbooks to reflect a decrease in estimated taxes but to my surprise it was the opposite.  It increased by almost $1000 per quarter.  Given I paid too much last year why would this be the case.  I of course want to do everything by the book but certainly don't want to just park thousands of dollars with the Federal government, dollars I could be using to pay down my own bills or help grow my business.  I also don't want to be penalized either though and I am looking for any insight anyone can offer here as to what the best practices/options are and why would claiming married with 2 dependents vs single and none actually cause me to owe more?  Also I received the estimated vouchers with what the government recommended I pay and the amount is significantly lower than what Quickbooks is reflecting so should I go off of that?  Confused on what is best here.