You're probably getting foam because your serving pressure is lower than the pressure that corresponds to the carbonation level in the keg. Let's say your beer is at 38°, which at your serving pressure of 9 psi corresponds to ~2.3 vol of carbonation. It sounds like you left it at 30 psi for ~50-60 hours, which would result in a pretty high carbonation level, much higher than 2.3 vol. By only applying 9 psi, the gas wants to come out of solution as it sits, and forms pockets of gas in the lines, which create foamy pours.
You need to decide what level of carbonation you want, and then consult the chart linked above to determine the serving pressure. If pockets of gas are still forming in the lines at this pressure, it means you overcarbed the beer, and will need to disconnect the gas and repeatedly vent the pressure for a day or two to bring the carbonation back down.
If there are no gas pockets forming in the line at this new pressure, but you're still getting foamy pours, the next thing to look at is the serving line length. The higher the pressure and/or temperature, the longer your lines need to be to slow the beer down and prevent it from becoming a foamy mess.
FWIW when I'm in a rush and use the carbonation method you tried, I only leave it on the higher pressure for ~36-40 hours, and then reduce to serving pressure.
Originally Posted by msppilot
ok next question is, how to i measure this? I can put a thermometer in the kegerator, but how do I measure the P.S.I in the keg?
Typically you don't. You set the regulator to the pressure that corresponds to the beer temperature and desired carbonation level.