My best friend and i are drifting away. advice?

you aren't over thinking this....believe it or not. im going through the EXACT same thing! omg! thats so weird. like, the exact same issues. lunch, lockers, meeting after class, im even in AP math too! ahaha! but no, i feel the same way. your not alone. its so hard. but i kind of am trying to lean on another more reliable friend, and not relying on my closest friend as much. that way, we're still friends, but i just find ways to offset what she doesn't do for me anymore. its normal for friendships to fade. this is an oppertunity to strenghten another one :) im sorry. your not alone. i hope thigns get better for you.