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.
