I'm guessing a X20XEV eco-top engine yeah?
Don't want to scare you buddy but throttle bodies are common as #!#!#!#!e on those engines, we used to sell LOADS for the vectra x20xev at my old work (I used to work for a vauxhall dealer)
I'd say thats a good guess, but dont take my word for it, its best to get it checked out, try taking it off and giving it a good clean out, and trying it again, if that doesnt help it, it may not be that
best bet is to just bare it and get it diagnosed if you cant figure out whats wrong >.<