I'm sorry for your loss. First, be aware that for 2016 you can still file Married Filing Joint and get his self-exemption for the entire year. The IRS says you can do that. Then for 2017 it depends on a few factors.

If you have a qualifying child dependent, then you can file widowed. This allows you to retain the benefits of the Married Filing Jointly status for two years after the year of your spouse's death. You must have a dependent child in order to file as a Qualifying Widow or Widower.

If you have no qualifying child dependents, then your filing status will be single.