What you describe qualifies you as Head of Household status.
However, your 19 year old daughter MUST be a full time student. More information here: https://turbotax.intuit.com/tax-tips/family/guide-to-filing-taxes-as-head-of-household/L4Nx6DYu9
Also, review the IRS information to be sure. https://www.irs.gov/help/ita/what-is-my-filing-status
Sorry for the loss of your wife.
