Is it ok to be scared?

theres this totally AMAGING guy that i've know for years and we were best friends but became closer and then he moved away but we've stayed in touch and we're not datin but he's promised me many things when he comes to visit. when i look at ne thing online from him that other ppl can talk to him theres always so many girls that talk to him i dont want to loose him! is it ok that i'm so paniced or am i being obessive? to controling? over reacting?