why do i feel ugly and average despite being told im pretty?

i feel like i have imposter syndrome or something. ive been told by friends and family that im pretty, ive had random people come up to me and tell me they think im pretty, ive gotten attention on the internet before, and ive even gotten some attention from guys before although not much tbh and when i did it was always from weird guys (not even trying to be judgmental, they were genuinely weird and creepy). they’d ask me out after knowing me for like a day, or confess their love to me after knowing me for a week…

i feel like this makes me sound arrogant, but i genuinely feel unattractive. im 18 and still haven’t dated and barely have had any guy friends, i don’t rlly feel like im missing out on anything but it makes me wonder. ive even been harassed and treated like an insect by guys before. but i dont think its because of my looks because theres prettier girls than me and they never got harassed, they were treated like equals.

when i look in the mirror its not like i see anything horrendous, i just feel brutally average. i have average features, average physique, there’s nothing special or exceptionally beautiful about me. all the compliments i get feel meaningless or like they’re out of pity, or people only tell me that to sabotage me and my idea of myself.