sub boy21

right guys been having a bit of trouble with me heaters going hot then cold for a few weeks now but the gauge never went above half and today i went to a mates and when i pulled up i noticed water coming from the overflow so when the car cool down i refilled the water and set off home witch is only half a mile and by the time i got home the temp gauge was at the top so i left i a couple of hours and did a compression test and got these results 1=140psi 2=120psi 3=140psi 4=105psi and wondered if it would only be the headgasket or could it be somthing else aswell