i dont know what l feel

I have a boy best friend, we are friend for ever 1 year and half a year, we meet on online and we live far far away, like a long distance friendship.. We dint know each other in real life only on social media.. We chat, and call...and there's a day that change things,, we chat but little then one day he said that he have a girlfriend.. Her the thing the girl is one who confess to her so he agree and chatted me and introduced me to the girl and l get close to that girl and Like talking about there future together and putting a line like me and my boy best friend is like a sibling to each other and time past there like 5 months now and for some reason l felt something.. When they fight l help to fix it trying my best so they won't break up but for some reason as l siad my mind keep thinking of my boy best friend and there's many what if.. And l keep pushing my self not to lessen to it.. I felt like there's something messing..