Can my dad still claim me as a dependent if i do my own taxes? i worked in 2019 and am still under 18

YES your dad can still claim you.

CAN I FILE A RETURN IF I AM A DEPENDENT?

If you can be claimed as a dependent on your parents’ return, you can still file your own return so that you can receive a refund of taxes withheld.  (You will not get back anything for Social Security or Medicare withheld.) Be sure that on your own return you say that you can be claimed as a dependent on someone else’s return.

The question about whether you can be claimed as someone else's dependent is in My Info. Do not mess that up.  If you mess it up, either your return will be rejected or Dad's return will be rejected.