2001 Chevrolet Silverado 1500 Question: my a/c is not cooling

i noticed my ac wasnt working, so i bought a new can of coolant... the one with the gauge, it read 125+ psi. I drained it, because specs say it should be between 30-40psi. after draining it while it was cycling, it ramped back up to 100+ psi, i then bled it down until the guage read next to nothing, filled it back up to 35psi and left it cycling and it is still at 35psi, but the ac is not cooling... almost even blowing out hot air at times.