Don;t even try to stop the FSA, at this point, it generally won't be allowed anyway and you would technically be "covered" anyway.
You probably can't stop the HSA deductions either, without a qualifying "life event."
What you will do is contact the HSA bank and withdraw any excess contributions before April 15. The excess contributions will be added back to your taxable income, because you aren't entitled to a tax deduction, but you won't be subject to a penalty. This is not a normal withdrawal, it will probably require a special form with the HSA bank.
If you are having ongoing payroll deductions, there won't be any point in withdrawing the excess contributions until after the last deposit (presumably around December 31, 2021). And you still can withdraw money for medical expenses. It won't affect your tax return either way, because the contributions will still be added back to your taxable income.
