I am a college student who worked in New York for the summer. I live and file taxes in Massachusetts. TurboTax says my income is twice what it actually is. Can I fix?

I believe you are referring to your income listed on the New York return, which includes your Massachusetts income.

Your income on your New York return will include your income from Massachusetts. New York will then tax all of your income, but reduce that tax by the percentage of income your earned out of state. So, you will not be taxed on your Massachusetts income by New York, even though it will show as income on the New York return.