Launcher has no service

The Minecraft launcher no longer displays "Play" and will only let me Play Offiline, yet my internet is working fine with everything. When I change the profile, the launcher stops responding entirely for about 10 seconds. Then it takes me to the new profile. If I try to log out of my account and back in, it takes a while to load, then it says:
"We can't log you back in as ElectrixMC. Please try to log in again. (InvalidCredentialsException:Invalid token.)"