Sounds like you have a bad leak. The compressor will not run with low pressure.
You will need to find the leak.
I am not that well versed in ac repair but after the leak is found youll probably need to pull a vacuum on it to remove the moisture and you may have to replace the dryer. Like I said not very knowledgable on ac.
If you do not have the equipment youll have to take it to be repaired.