You cannot file as Single is your are legally married.  Did the "tax consultant" really mean your W-4 withholding form?

yes my w-4. I know which option to choose now thank you. I should choose married but withhold at higher single rate.

I agree.  If both spouses work, it is usually appropriate to claim "Married but withhold at the higher Single rate" on the W-4.  The "Married" withholding on a W-4 is mostly based on if only one spouse works.

Of course the W-4s for 2020 are most likely going to dramatically change, and are pretty much like doing a tax return.

Thank you so much for all of the info. I didn't read the W-4 correctly and should have chosen the married but withhold at higher single rate option. With that should I still claim additional allowances? (1 for myself and 1 for married filing jointly?)

No way for us to know.  Depends on how much more you need to have withheld by the end of the year.

(VERY ROUGHLY) For a person being paid twice a month at 2000 gross per paycheck
Withholding/paycheck for married and zero allowances is $165
Withholding/paycheck for single  and zero allowances is $240

so ~$75 more per paycheck is withheld by going from M to Single and zero allowances on both.

IF you were doing Married and 2 allowances last year and switched to Single and 2
then it goes from 125-to-170  or $45 more per pay
_____________
So you should be able to figure out from that ~how much the extra withholding will add in to your total by the end of the year.

(But, of course, that's for ~2000 gross /paycheck twice a month)

thank you!