Is not weird.. In New York City the high school gave locker rooms. Everypone get to see each other with bra and panties.. and if u dont feel comfortable then do it in the bathroom. It's perfectly normal aslong as if she's a girl. Best friends are like sister.
Like don't keep him in your mind constantly. Like hang out with friends and go out to nice places. That'll just keep you strong. Also just keep writing him letter and things will get much better :)