No access to my account

Help, I don't have access to my java account. At the beginning I created a java account. I chose the username Greatwrath1711

Nowdays... When I open the launcher, it says I haven't created a profile. When I try to launch Java it says "Enter a username for Minecraft: Java Edition"

When I try to type my name it says Username has already been taken

How do I get back access my account?

EDIT: This happens a few times