How do you feel if somebody is following you?

i was walkin to the shop last week and i was all dressed up because i had been to a party i was a bit drunk and i had th feeling somebody was following me but i dont know wethe it was me bein stupid or i was gettin followed becuase recently a man in his mid 20 has been everywere were i am and im actualy scared to go out but i dont know who it is i have livd here all my life and i know a lot of people but i have never seen him before what should i doi have told my parents but they just said stop being stupid and started arguing again but i dont know wether to go to the police because he follows me even when i am in a group with my friends what can i do??