Mostly he just said I shouldn't have had that problem in the first place.
But you're right. I'm assuming that's something I would do through payroll? Guess I need to find out.
Irrelevant and unhelpful!
It probably is your exemptions. All you have to do to update it is to fill out a new W-4 form and turn it in to payroll. Something I did years ago when I knew I was going to have extra side income was to add a specific amount to be taken out of my check for income taxes. There's a place to specify that on your W-4 form as well. That was when I had a $300-350/month check that had no withholding taken out at all, combined with my regular 40-hour/week salaried position. It saved my bacon that year. However, if your exemptions are incorrect, that's probably all you have to fix.
I got stuck last year with a $2,000 tax bill that I wasn't expecting due to an inheritance payout that was supposed to have been awarded post-tax. I was selling everything I could get my hands on to pay that one, so I can identify with your dilemma. That's why I saved up extra this year to pay taxes, and then I didn't owe anything but got a refund. Sheesh! Why couldn't that have happened last year, when I really needed the extra boost???
Sometimes, I'm convinced someone is playing around with the tax code in just such a way as to keep us all off-balance all the time.