how to stay friends after a break up

my boyfriend and i began dating two years ago and now i’m 17 and he’s 18. he is the most selfless person i’ve ever met and i enjoy his company but i fell out of love with him and for a while i’ve realized i would rather be friends. I also noticed that i am not that secure with myself and i’m not mature enough for such a serious relationship at 17 and i need time to learn more about myself. My insecurities would be taken out on him which he didn’t deserve and i know it’s coming from a side of me that feels trapped in this relationship. He respected my decision even though it’s hard on both of us right now but we both want to continue to hangout and text but not as often. This choice was hard but i know both of us will be happier not being so attached to each other and i feel its better now than by the time i go off to college. we don’t just want to cut each other out of our lives after so much time knowing each other. I know i won’t try to kiss him or anything and i know he wouldn’t do anything to make uncomfortable but i’m worried that if he still has strong feelings for me it will be hard to be friends. Also i don’t want to get back into a relationship but i’m worried if we hangout too much it will basically turn into that again.

Does anyone have advice on how to successfully be friends with an ex?