I just migrated my account on Minecraft and I want to know if theres anyway I can get my...

I had a lot of bought stuff on that account including my username which is 3 letters. I didn't have the chance to migrate because my email was lost and I couldn't get on it since it was on my old phone. I got my email back and I log in and I migrate and I open the launcher and it tells me to enter a new username whenever I hit play. Did I lose my username and all my stuff?

:)