My question is: Can I claim the remaining amount (10500 minus the 2000 something I already contributed) and deduct that amount from my taxable income?
No
Or I'm stuck with the 2000 something in my FSA?
No
you complete form 2441 Child and Dependent Care expenses
here's how it works for 2021
A) actual expenses are limited to $8K for 1 qualifying dependent or $16K for 2 or more qualifying dependents. this is reduced by the dependent care amount
so for 1 dependent the limit wound be $8K- $2K = $6K
for 2 or more $15K (your actual expenses are less than $16k) - $2K = $13K
B) the lessor of the following:
1) the amount from A)
2) your earned income
3) your spouse's earned income
C) then if your AGI is $125K or less 50% of the amount from B
if your AGI is over $125K see page 7 on form 2441 instructions for % to use
if your AGI is over $438K you get nothing
https://www.irs.gov/pub/irs-pdf/i2441.pdf
the result is a tax credit that flows to schedule 3 line 2
