Can I get a hardship withdrawal from fidelity to pay back Federal Taxes?

In general payment of taxes is not one of the generally accepted reasons for hardship. Have you already contacted the IRS about setting up a payment plan? That should come before you seriously consider a hardship withdrawal from your 401(k).

Here is a good web site that covers hardship withdrawals:

401khelpcenter.com - 401k Hardship Withdrawals