scorpio friend confusing

we are friends for a year and half a long while, we live in different cities, so we communicate through( texts,emails, phone calls)the thing is:three weeks ago he's been acting in a way that i don't understand, we used to chat on Skype but now he doesn't want to talk,if i need something he say to me to leave an email, so i sent him a message 2 days ago he read it but didn't respond, i don't understand what is going on, because to other people he talks normally but with me it's different, between him and i it's purely platonic we are not a couple and i don't think of him that way and he knows it, a very long while back he told me that he'll visit a nearby city to the one i live in for business, and if while he's there we'll meet, at that time i said yes i will,but due to some personal issues, he visited the city and i couldn't make it,but while he was there we texted each other and i think from talking to him it didn't seem like he was upset,now i can't even tell him the reason why i didn't make it because i tried to talk to him, he would say that he's busy and doesn't know when he'll have time and to just leave an email and he'll answer, between this situation began before that this happen, can you explain this to me? * sorry it's long*