Maybe you'll find this helpful?
Here is a grading tool I made on Excel that will help with keeping track of your answers and then semi-automically score it. Follow the steps below and make sure to click "Enable Edit" at the top of the excel sheet.
Download the Medicine grader
1) On the bottom of the sheet, ensure that you’re on the correct tab for the form you’re currently taking.
2) Input your answers as you go along, starting at Box A1, and moving down the column.
3) Once you’re done, on the bottom of the sheet click on the appropriate form’s Answer tab, highlighting and copying the correct answers.
4) Return back to the original form with your inputted answers then paste the correct answers starting at Box B1.
5) The excel sheet should then automatically grade that form and your % correct will be found on the bottom of the answers columns.
NOTE: this % correct may be slightly different from the "Equated Percent Correct" (EPC) score that the official NBME form gives you, as NBME compares your score with other students and how they did on each questions. Just be aware that your raw % score may be +/- 3% of the EPC.