I lost my data

I play in EUNE nuke16 was my ign but when i logged in it asked me to change my username and my ign name and i changed both and now when i logged in on the new username it logged me in on a different account and when i search my account-nuke16 on OP.GG or in any other page my account is still there is this a bug or what happened to my account i seem to be the only one that this happened to, i spent alot of time on that account and its just sad losing it for no reason.