I have always thought of taking a $300 course (or may be less) at Liberty Tax or HR Block or similar places after Tax season....where they teach you how to pass the exam and become a an IRS certified Tax Preparer - One time investment...valid for decades -as you can confidently file your own taxes every year afterwards (maybe)...... Please check some articles online if you don't get the answer you are looking for..



Togetherness or not?
Separate returns could produce tax savings if one spouse has a lot of medical expenses and a low income. By filing separately, the partner with the doctor bills might be more likely to exceed the 10 percent of adjusted gross income threshold needed to itemize medical costs. Taxpayers age 65 or older can still use the 7.5 percent threshold for their 2016 tax filing, but the 10 percent threshold applies to everyone in 2017. Only one spouse on a joint return must meet that age to get the lower deduction percentage.

Deduction flexibility also is sacrificed. If one spouse itemizes, both must itemize, splitting the items to be listed on a separate Schedule A for each. That means a partner with few deductions couldn’t use the standard amount and might get cheated when it comes to reducing taxable income.

Deduction, credit considerations
Many tax-cutting credits and deductions are forfeited when couples file separate 1040s. You can’t take the earned income tax credit, claim adoption expenses or child and dependent care costs, use educational tax credits or even deduct the interest you paid on a student loan if you’re married and filing separately. If you have children, you might find the child tax credit reduced because it phases out at different income limits for the various filing statuses. And the amount of capital losses you can deduct is cut in half."

https://www.bankrate.com/finance/taxes/filing-taxes-jointly-a-good-idea.aspx .