It sounds like a lot, but it depends on what your COMBINED total net take-home pay is, between the two of you. It is usually a formula, at least for the child support, based on your combined income. Is part of that alimony? There are no set-in-stone numbers for that...although alimony is tax-deductible to you, taxable income to her.
The money is the most straight-forward piece of this...do you have counsel to look and help you think clearly at this?