Shows my old username after I changed it.

I changed my user name to Ech0Art today, and when I hopped on to MC the launcher showed my username as my old one (Crescent_Candy). I did a the most sensible thing I could think of and I restarted the launcher, but is still showed up as Crescent_Candy! So I thought "Hey! Maybe its just a glitch in the system and it will be fine once I get into a server!". So I did just that and it said "ERROR username could not be found" So now I cant get into servers. Then I got into game it was STILL Crescent_Candy but at least it didn't turn me away.