walk in cooler charge

I have a walk-in cooler with two 4 fan coils each costing $27,000, two 18x6 receivers, one 14x5 accumulator, and roughly 50–60 feet of line set. The sight glass kept bubbling, and the outside temperature was 40 degrees. I replaced the headmaster since the head pressure on a 407a unit was approximately 120, and I was able to raise the pressure to 185, but the suction was only 20 psi. The head pressure rose to what I considered to be an absurdly high level of something like 280 or a condensing temperature of 108 with the ambient that cold. I calculated the total volume of the receivers at 90% and the other factors, and came up with something like 54 pds, but the glass was still bubbling.Until I cleared the sight glass, the indoor coil appeared to have softly frosted over on both sides and the txv and distributor tubes were all covered in ice. The distributor tubes remained a block of ice. Do you think this device is overcharged? Suction pressure is now at 35 psi or 14 deg coil with a 38 deg box, and I'm scared that when it gets heated, my head pressure may go crazy. Since this system has been operating this way for years, I did not change any txvs. Do you have any ideas?