relationship advice :(

i’m 16, my boyfriend is 15. we’ve been dating for about 3 months now and he recently broke up with me because he “lost feelings” even after i asked him 3 times if he was losing feelings. he was so quick to unadd me from snap and unfollow me on instagram too. he didn’t even want to talk about why. his friends told him how bad he fucked up and he apologized. I went to his house a few days after and i talked to him about it face to face and he told me he lied about losing feelings because he felt bad. i took him back but i’m really nervous. how do i know he’s not lying to me now because he feels bad for me? what are some red flags i should look for and is there any way i could make him more interested in me?