Both of your guys replies here are confusing and adding to the confusion in this situation.
You can have a different minecraft name to that of your microsoft account name (Mine is different, it is possible:
https://help.minecraft.net/hc/en-us/articles/4408950195341-Minecraft-Java-Edition-Username-VS-Gamertag-FAQ). If the premium name for mclovin is available feel free to change it back to it, there would be nothing for us to do on our end as you have joined under the same username.
Second, you could join using a cracked launcher with the username mclovin, again here there is nothing else which would need to be done on the serverside as you have joined using the same username as you have had before.
If you want to change your username this would mean an account transfer. Do think it over and do tell us which approach you would be taking.