Praise be to
Whoever passes the meeqaat without entering ihraam
has to go back and enter ihraam from that point. If he got off the plane
in Jeddah, then he has to take a car to the meeqaat of the people of
Najd and enter ihraam from there. If he enters ihraam from Jeddah and
he is intending to do Hajj or ‘Umrah, then he has to offer a sacrifice
as expiation for passing the meeqaat (without entering ihraam).
Fataawa al-Shaykh ibn Jibreen
See also similar fatwas in Kitaab Fataawa
You did the right thing by going back to the meeqaat and
entering ihraam from there. The fact that you took off the ihraam
garments does not mean that you have to offer the sacrifice, because
you did not enter ihraam in the first place. Ihraam means the intention
to enter the rituals, not just wearing the garments of ihraam. Based
on that, what you did was correct and you do not have to offer any kafaarah
(expiation), praise be to Allaah.