Thanks to everyone for your responses. A follow up to my flight. I used my passport that had all the 3 names instead of my DL and everything was perfect. I am glad I did not pay the absurd $150 "name change" fee !!
And you can bet,I will be extremely careful the next time I am entering my name. But I just dont know how I could make such a silly error?? I buy a lot of tickets online for my family and me and never have done this.. But yes, I am even more careful from now on !!