Seems like an instance of the well-known "Michael Bolton Problem" from Office Space. You had a name, you were using it, but something significantly more notable comes along with the same name. They didn't steal your name, but by virtue of being much more popular, now nobody thinks of you when they hear your name, they think of the other thing that you have no association with and came after you.
There's no theft, just an annoyance for you. You were probably never going to be famous, but now it is much harder. On the ironic upside, people who didn't care about you before now remember you, because of the naming conflict.