2003 7.3 A/C

Hello, having an a/c issue that I can't find a thread that relates. My 03 f 250 was blowing warm air. Checked the air gap and was over .045, got it back to .021, blowing cold air again, but the compressor now will not cycle. The compressor comes on and blows cold air, but will not cut off. I got a pressure reading on the low side of about 23 psi. Also, I tried adding coolant to the system and it would not take any. When I first put the gauge on the low side and kick on the ac, the pressure starts at about 28 and falls to 23 psi.

Any thoughts would be helpful