Name change

So this may be a dumb question BUT I did Google it & I just got even more confused LOL.

When I got married 4 years ago, I signed with his last name. That's literally the only thing with his last name on it besides my dependent military ID which expires next year anyway. Nothing else of mine has been changed. So am I legally his name or mine? Makes sense?

I got second thoughts today for no reason & I truly dont want his last name. Thanks for reading! 💓