When you transmit on your radio and can hear yourself, this is called "sidetone". It is desirable to be able to hear yourself speak, as you have discovered. As long as your radio is transmitting to other airplanes, ATC facilities, or whoever else, this would indicate that your mic button is fine. The sidetone on your radio is out of adjustment. Most radios or audio panels have some kind of adjustment to change the sidetone volume. Good luck.
