If you were legally married as of 12/31/2019 and living together at any time during the last six months of the year then you can only file your 2019 tax return as either Married Filing Jointly or Married Filing Separately. There is NO other way to file your tax return.
You should try and agree to file jointly since you have children. See this TurboTax support FAQ for filing jointly versus separately - https://ttlc.intuit.com/community/married/help/is-it-better-for-a-married-couple-to-file-jointly-or-...
