i was pulled over because the officer said i wasnt wearing my seatbelt , when i asked the officer a question he said i gave him probable cause to sear

The swat team ambushed my car because they say  I wasn't wearing my seatbelt, which I always do. I had p/up 2 friends that had been drinking ,to take them home. When the officer asked me if I knew why I was pulled over , I told him , I no because I honestly had no idea. The officer said "because you were not wearing your seatbeat" I politely said "no sir I always wear it" & looked down at my seatbelt . The officer then asked for the proper paperwork which I produced again w/respect. Now as this is going on  at my window , I can hear the officer at the back passengers door , which by the way was occupied by a 21 yr old that these officers where completely intimidating & scaring half to death, when I asked them why they were treating us this way, I obviously triggered  something w/in him that he did not like. After he called all my info in & found out i had a clean record,  this frustrated him even more & he asked me to step out of the car for a field sobriety test stepped out of my car