More detail is needed. What are your high and low system pressures? Is your blend door operating properly? Blindly adding refrigerant is a very bad idea, did pressures or symptoms such as rapid compressor cycling suggest you were low? How did you check for leaks? Is the compressor clutch engaging?

Willy-nilly adding refrigerant is a potential recipe for disaster. For starters, if you used a so-called easy-fill recharge can that you got at an auto parts store, the refrigerant has been contaminated with air. If you used a sealer of some kind, that's even worse. Many mechanics won't recover refrigerant that has been contaminated with sealers because it ruins their equipment. Air doesn't behave like a refrigerant. It doesn't turn into liquid when it's compressed and enters the condenser, it remains highly pressurized air. Likewise, when air enters the evaporator, nothing significant happens. Liquid refrigerant evaporates in the evaporator, cooling the inside of the car. Air remains air and doesn't produce the same effect. And the amount of refrigerant required by the car is in the order of maybe 1 pound to 1.25 pounds (my Ranger takes precisely 20 oz of refrigerant). Any deviation from the specified amount of refrigerant and the air conditioner will not cool properly.

Take the car to a mechanic who specializes in HVAC, air conditioners are EXTREMELY dangerous if you don't know what you're doing; typical low-side pressure is 45-55 PSI in a properly running air conditioner, and the high-side pressure is in between 225 and 300 PSI, depending on ambient temperatures outside the car. For reference, the pressure in a typical passenger car tire is only around 35 PSI. Given that the vast majority of the conduit in the air conditioner is also made of metal, you can seriously injure yourself.