HOW TO STOP FALLING FOR SOMEONE YOU HARDLY KNOW?

i have this friend, we've known each other for 4 years, but, we never hang out together, we only text for that whole 4 years. and now i am confused if i am really falling for him, bec he does to me, he once told me those 3 words but i rejected him, and now it all comes back, i think i like him, but there are certain questions in me, like how will i fall for someone i barely know? what am i going to do? i don't wanna fall in love too fast. Thanks. :D