If someone suspects that he is being spied on by his phone

I gave my phone and email to a sketchy person(for some reason,and yes i know it was stupid),and now I suspect that I am being spied on.should i change my phone or it doesn't matter because he got my email therefore he can access anything that is connected to my Google account.and keep in mind that changing you're life long Google account isn't easy.

SO I DIDN'T KNOW WHO TO ASK SO I CAME HERE.I HOPE ONLY PROFESSIONALS WILL ANSWER ME AND THANK YOU.