the worst call ever

so i was feeling really down last week after a brutal midterm and just wanted some comfort so i messaged my best friend from undergrad who's always been supportive. we've never had any sexual tension or anything but she's super cuddly and affectionate like an older sister to me. anyway, she offered for me to come over and spend the night watching movies on her couch which seemed great till halfway through this chick flick i start feeling all tingly inside. next thing i know i'm practically panting at my friend as she strokes my hair trying to cheer me up and it's just too much. so i get these butterflies in my stomach and i end up telling her that i need some space cause its confusing me but now i feel terrible because my friend is probably really hurt by this and i have no idea what to do or if i should explain further. im worried i've ruined our friendship over a moment of lust. any advice?