Idk what to do

So idk what to do but I went swimming today with a friend of mine and all of a sudden he grabbed me and untied my bathing suit and pulled my bottoms down. After many attempts to get him off and to stop touching me I punched him in the face and left. Why do guys have to ruin things. 😒 my boyfriend was at work so I didn't tell him I was hanging out with this guy. But he knows we are friends and trusts me. Idk if I should tell him cause babe with fuck his world up