What tf do I do/how to stop being this weak?

um so my class teacher has been flirting with me? at first i thought i was being paranoid but my best friend said she noticed it too. he'd ask me to stay behind class and help him carry his files and notebooks to the staff room and ask me questions about my personal life. they're not THAT intimate or whatever but i just feel uncomfortable answering them. sometimes he just stares at me in class, or like touches my lower back anytime i need help with a question and well i feel weird typing it like that.

i've been trying to avoid him, coming late to his class and stuff but i still feel really uncomfortable. i want to tell someone but I don't know who. my bestfriend knows, and she told me to tell my parents but like, we're not on the best terms and i dont have the courage to tell them. i really want to, but talking to them about ANYTHING feels really embarrassing and awkward. i dont have the guts to tell another teacher too. i thought of asking my friend to talk on behalf of me but i dont know? it feels weird asking her to tell another teacher "our class teacher is flirting with ****** do something" I don't know?%? pls when god sent me, why didn't he send me with courage
What tf do I do/how to stop being this weak?
Post Opinion