My owed taxes are much higher than normal, which is why I think I'm paying double taxes on these stocks. I'm wondering if there is a form I can fill out that will show I should only pay the taxes once.
When you sell ESPP stock, it is possible that you will owe both ordinary income tax as well as capital gains tax. This TurboTax help topic explains:
https://turbotax.intuit.com/tax-tips/investments-and-taxes/employee-stock-purchase-plans/L8NgMFpFX
You shouldn't be taxed twice on the same dollars, though. For example, suppose the share price of ABC Corp is $100, and you acquire a share at a discount price of $80. Later you sell the share for $110. You have $20 of taxable compensation from working, and a $10 capital gain. That's normal. You should not be taxed on $30 of capital gains on top of paying the tax on $20 of compensation. If you think that is what happened, we will need some more details to help you figure out what happened.
Did the sale show up on the W-2 and the again on the 1099-B from the broker in the same tax year ? If so you need to adjust the cost basis on the 1099-B to reflect the taxes paid on the W-2. Your employer should have provided the cost basis for you if the broker doesn't have the correct information. Usually the 1099-B will show a loss in the amount of the broker's fee if it is done correctly.