I have no idea if I was sexually assaulted and idk what to do

When I (19F) was younger, maybe 8 or 9 I vividly remember a time where my older male cousin was playing a game with me at a party in my room, I’m not sure if it was sexual or not but I remember him getting on top of me pinning me down and moving around on me, I remember struggling a lot and asking him to get off but he didn’t, until I screamed and then he got off, I remember for a long time after having a horrible feeling of shame and disgust with myself and being very scared of this cousin, I have no idea if this was assault or just playing that got misinterpreted, I know that no one can tell me if this was assault or not but any tips for how I can figure this out? Idk if maybe talking to a therapist could help