What would oyu do if your BEST FRIEND did this to you?

So I have been friends with this kid for about 6 years and he is not the coolest i am nice and caring, i met a new group of friends throughout 5th and came rreally close with them in 6th and so did he but the bad thing is they changed me a bit but he changed to, so one day i send him an email with a funny APPROPRIT pic. he said "Stop or i will report you to spam" and then i said what is wrong with you lately? then he replied that i was a terrible friend ( which i never was i was his only best friend and so nice to him) so he was friends with this really other gross kid that is to nasty for words which he would sit with us at lunch then scare my friends away so i asked him not to let him sit there so he also menchined that to and he also said none of my friends will ever stay my friends then i told him he was crazy, then the teacher found out and then he was lieing to her but i just let it go, then one day i went up to him and told him and said this " hey um i would really appriciate if you would stop talking beihide my back its rude!" and he said well i just want to punch you right now (hes scrawny so i wasn'tt scared) i said WELL GO AHEAD YOU DON't THINK I WANT TO, then my friends saved me hahaha then a week later i handed out b-day invites and got pissed off that i didn't give him one so he told the teacher then i pooled him and the teacher both outside and i said, " i did not giv you an invite because were not friends why would i do that?" then at the last week of school, he told the teacher for a stupid reason which was a lie and made my best friend cry over it. so yea now were not friends anymore and i don't mind it... and for some reason hes scared of me, but now i have the best friends ever i could even ask, so i think i took it pretty good, how would you have done or handled this?oh and, the first week of 7th grade i tried to talk to him but he just walked away, now its tward the end of the year and i am getting freaked, he is buying the SAME EXACT close as me, died his hair my color, baught vans like me, wheres black socks like me, now uses a blue gym bag like me, tries to talk like me, its freaking me out! What do i do? and what do you think about that? isn't it rediculous?