I have filed as head of household in the past but this year it is telling me that i should file single. Will that exclude me from filing hoh in the future?

No, not in and of itself.  Your filing status is determined on a year-to-year basis.  If this year you are not claiming any dependents, you must file as single.  However, if next year you do have qualifying dependents you may claim, you will once again be able to file as Head of Household.  And if you get married, you will file either Married Filing Joint or Married Filing Separately.  Claiming Single this year will not impact how you will file next year.  You will file next year with the most tax-advantaged filing status you qualify for.