What you probably did was contaminate your system with sealer. Those aftermarket cans of refrigerant always contain sealer and more often than not do nothing more than to expand your rubber fittings, but try to use them on a recovery machine and it clogges them up. Those aftermarket kits are good if you are selling your vehicle and don't feel like paying big bucks to get the a/c serviced, but personally I would never do that again if I am planning to keep the car for a while. Plus, I never trust those gauges either as you low and high side pressures fluctuate based on the weather temperatures. The best way to get efficiency out of your a/c is to take it to a shop and have them fully evacuate, recover, vaccum, and re-charge, that way you get the proper amount of refrigerant charge in your system and flowing through the evaporator to cool (refrigerant actually changes from a liquid to gas in your evaporator, which acts as a radiator sort of speak, since your evap is like a heat xchanger).