reactivat old yahoo messenger account i changed accidentally on May 3rd 2018?

Instant messenger no longer exists. It was closed in July 2018: https://help.yahoo.com/kb/SLN28776.html

Yahoo Messenger will no longer be supported after July 17, 2018. That is when it was discontinued and removed. It did not exist after that date.

i think they took yahoo rnessenger out forever

You're too late. Verizon has shuttered it a little more than a year ago.

Verizon terminated Yahoo messenger on July 17, 2018. We were warned in may that you had 3 months to save stuff. Verizon is not going yo bring Yahoo messenger back and you or Verizon staff cannot revive it.