trauma advice?

tw: assault

earlier last year i was physically assaulted by someone who was previously my friend. he really hurt me, and i've been scarred for months. the thing is, the only person who believed me was my mom. all other adults i opened up to said that boys would be boys and that i would have to switch schools to cope with wanting to avoid him. he was still included in my friend group even after this, and our mutual friends didn't really care (one did, but only cause he had a thing for me and stopped defending me after i rejected him). i've lacked a lot of validation in my experience and feelings.

does anyone have any coping skills, advice, or words of encouragement?