Whats wrong with my 1998 S-10 Chevy Blazer?

Alright so today while driving my blazer got super warm temp gauge all the way up pulled over and coolant was boiling in overflow tank, let it cool down enough to drive back home and changed the thermostat, but still overheats and also leaks from somewhere i can not really see, took bottom skid plate off but having hard time seeing where the leak is coming from, so basically could this be the freeze plug, water pump, idk need help fast.