how do i bind without a binder/kt tape?

hope i used the right flair. basically, i'm 17 & have already come out as trans to my family. i don't think we could afford a binder or anything right now but my chest dysphoria is getting bad and idk what to do. when i was around 12 i used duck tape a few times but that's not the safest. i tried using sports bras but they don't do much so i'm wearing using baggy clothes and hoping. for reference, i was blessed with a smaller chest (A or AA maybe?).