2002 ford escape ac no cold air but refridgerant is full?

AC in my Ford Escape has no cold air. Was gradually losing cold air the last few days. Heater works fine. When I tried to add refridgerant the gauge on the can said 150 psi without even pulling the trigger. When I pulled the trigger to let out the refridgerant it would go to 0 psi. Yes i an positive i was on the low side port since it would not fit the other port. So it sounds like it's at full. No refridgerant has been allowed to be dispense from the can. I assume it has no leaks. I have honestly not checked fuses yet or relays but that is the next step that I would assume. I just wanted to see if anyone has any insight on the possibilities that it could be some other issue. It's been working fine for 2 years straight since I bought it and fixed it initially in 2012. It is a 12 year old car after all.

Hi so what about the air conditioning compressor or the heat exchanger. This needs to be checked out by a specialist air conditioning engineer.

Try and look at either your compressor, the cluth might not be engaging or it might be engaging rapidly! Or the accumulator might have a ruptured desiccant bag which is inside the accumulator.

A trip to the mechanic is most likely going to happen but I was wondering if there was something a lot less expensive I could try. I'm a father of 2 and bills up the wazoo. I may not have a way to afford a major fix and it's the hottest times right ow in Florida. I've never had a good experience with cars and AC. My bad luck.