Whenever you use a transporter you die and get cloned.

LAFORGE: Apparently there was a massive energy surge in the distortion field around the planet just at the moment you tried to beam out. The Transporter Chief tried to compensate by initiating a second containment beam.
DATA: An interesting approach. He must have been planning to reintegrate the two patterns in the transport buffer.
LAFORGE: Actually, it wasn't really necessary. Commander Riker's pattern maintained its integrity with just the one containment beam. He made it back to the ship just fine.
CRUSHER: What happened to the second beam?
LAFORGE: The Transporter Chief shut it down, but somehow it was reflected back to the surface.
PICARD: And another William Riker materialised there.
RIKER: How was the second pattern able to maintained its integrity?
LAFORGE: The containment beam must have had the exact same phase differential as the distortion field.
RIKER: Which one of them is real?
LAFORGE: That's the thing. Both. You were both materialised from a complete pattern.
CRUSHER: Up until that moment, you were the same person.

If it does just copy you, then the transporter is pretty much a fancy suicide booth.



MinutePhysics [. . .] explain that scientists began looking at a thing called quantum teleportation in the nineties. This is the process whereby quantum information – such as the state of an atom–- could be transmitted. However, a major clause in this theory is the “no cloning theorem.” Essentially, to create a replica of a quantum state, the original must be destroyed in order to obtain all the information.

Science is still pretty shady on what exactly constitutes consciousness and what makes you “you,” so it's still hard to say. However, if it was something to do with the quantum state of certain electrons and atoms in our brain, then it doesn’t look too hopeful that “you” would survive the journey.