Print your return and actually read it. While the rules that control what goes on each line are sometimes complex (not any more so than rules for an IRB or IACUC protocol, though) the form itself is a straightforward math problem. You should really print and read it before you file.
If your only income is a $30,000 fellowship, then your tax would be about $1800. ($30223 gross income minus $12,400 standard deduction = $17,823 taxable income, the first $9700 taxed at 10% and the rest taxed at 12%.)
But $4278 is not the correct tax if you had incorrectly reported the income as self-employment, it would be higher than that. $4278 is also way too much to be the regular tax on your income plus a penalty, the underpayment penalty plus interest should be no more than 12% of the amount of tax you owed.
So something else is wrong with your return. You have more income listed somehow. Did you get a 1098 for your tuition waiver and that was somehow added incorrectly to your taxable income?
Generally speaking, you should have a form 1040 with lines 1-6 blank (income). You should have a schedule 1 with your fellowship on line 8 with "SCH" or "fellowship" listed on the line next to the amount, and no other entries on schedule 1. The fellowship on schedule 1 line 8 should be copied over to form 1040 line 7, and that's it. You should have no other forms as part of your return. Anything else means you either had a more complicated tax situation than you described, or you got some wrong numbers into your tax return somewhere.
