Alright then, hopefully its as simple as it sounds.
In pressing your power button as many times as you said, you triggered a "feature" if you will, where the PC's bios partially resets some settings that (at its best guess) might be causing the reboots (this would be your OC settings). It does not take into account that you might be pressing the button, or that the power might be blinking rapidly, as these things can both falsely trigger the feature and cause the issue you have described.
It sounds like your PC came possibly already "factory overclocked", like if you bought it through some online store pre-built. I know some places do that. All you have to do is determine how the settings were configured when you first got the thing. Tech support at where you purchased might be able to help. Otherwise you're left to guessing or telling us your specs and letting us research optimal settings combinations. Some motherboards have "safe steps" built in though, where the board is able to determine "safe" OC settings and it will apply them, reboot, test, and you can do this again and again until you find one that works. Most boards hit a good safe low OC combo the first attempt. Past that tends to be hit or miss.
Alright its your turn to return a wall of text