My teacher got offended because I said thanks instead of thank you sir

I can't fucking believe it I try being nice and he thinks I disrespecting him. I feel terrible and small. I see myself as a very kind and nice person and this experience damaged my vision of myself. The worst part is I know this will not leave me for a long long time because I remember my teacher getting angry at me in 4th grade and I think about it every week☹️