How do i get comfortable around girls

So recently i moved to new city for ug and all my life i have seen woman around me wear clothes up till neck , maybe a lil bit of cleavage but nothing much but here like in movies i see some girls ​wearing very revealing tops like bust is almost exposed till naval , i get really uncomfortable around them and also kinda get horny

I dont stare at them( yes i do end up looking) , then when i go back to room i end up masturbating thinking about them, i had porn addiction before but got rid of it but i cant seem to still control seeing girls in tiny thong bikinis or exposing their cleavage like this.

Even i do same with insta pics whenever some hot gal in revealing clothes come in feed

My friends tend to look at those girls and gasp but they dont go around masturbating, seriously i feel so guilty afterwards , how do i fix myself, i had my exam 2 weeks back , saw some girl in uni like that , even though i knew i had to go back i study , i couldnt get her out of head and ended up doing the deed. its affecting my life a lot