Are withheld taxes everything your employer took out of your gross. Bc my w-2 has way less reported than what I give.?

Don't understand your question.  But no, there can be other items deducted from your pay like 401K contributions and health ins, etc.  ask your employer.

Yes, withheld taxes are what your employer withheld from your wages.  Your W-2 should generally match your final check stub of the year for taxes withheld for federal, FICA, state and local.  Each item is separate.  If you have other things deducted from your check, this would not be part of your withholdings. 

The payments you make outside of your employee withholdings are not accounted for anywhere on your tax forms you receive.  These you must track and then enter on your return under Deductions and Credits>>in the Estimate and Other Taxes Paid section under Estimates.