Yes, you had a pro fight, you are a pro fighter. There is no implied winning in the term fighter. People should have more respect for the loser of a fight.
There also shouldn't be such a taboo on losing/failing, in general. If you are afraid to fail, you won't risk what is necessary to evolve and improve yourself and what is necessary to reach your goals. At least, that's if you listen to your fear.
We all make mistakes and we all fail. No need to delegitimize someone's endeavor or occupation, because it didn't work out the way it was intended. You still tried to win and you fought, so you are a fighter and you did it for pay, so you are a pro fighter.
And you are planning to fight again, so it all applies currently. It's not like you are retired, either.