Since you are still married you have the option to file a joint return. If that is not your choice then you can file Married Filing Separately OR Head of Household if you qualify. No injured spouse form is required if you don't file jointly.
https://ttlc.intuit.com/questions/2567672-can-a-married-person-claim-head-of-household-filing-status
Is it better to file
Joint or Separately?
https://ttlc.intuit.com/questions/1894449-is-it-better-for-a-married-couple-to-file-jointly-or-separ...
