You got some incorrect information somewhere or from someone.  There is no rule that says you have to wait a few years to file HOH again.  If you meet the criteria to file as HOH then that is how you can file.  Did you have a qualifying dependent to file HOH for 2019?  If so, then amend your 2019 return.

Am I Head of Household?

https://ttlc.intuit.com/questions/1894553-do-i-qualify-for-head-of-household

https://ttlc.intuit.com/questions/2900097-what-is-a-qualifying-person-for-head-of-household

If you qualify as Head of Household, when you enter your filing status (single or married filing separately) into MyInfo, and then enter your qualifying dependent, TurboTax will offer HOH as your filing status.

https://ttlc.intuit.com/community/amending/help/how-to-amend-change-or-correct-a-return-you-already-...

Related Information:

·         What does it mean to "amend" a return?

·         Do I Need to Amend my Tax Return?

·         Will amending delay my original tax refund?

·         What is the deadline for filing an amended return?

·         Can I e-file my 1040X to amend my return?

yes, I do have a qualifying dependent. 

If you lived apart from your spouse for at least the last six months of 2019 then you could file HOH for 2019, and HOH going forward if you still have a qualifying dependent.  That stuff about not being able to file HOH for a few years was wrong.