Air Conditioning Woes

[jcbiddulph]

Hi Guys first post here apologies if it's in the wrong place. I have a Blobeye WRX with some Air Conditioning issues.

The A/C Clutch doesn't engage, I checked the fuse and relay both are fine and there was pressure in the system. I then jumped the relay which caused the clutch to engage and the pressure go to near zero. I waited about 2 minutes and then filled up the system to the bottom of my cans green section however now it gives me about 5 seconds of cold air before the pressure rises quickly to 'warning'  and the belt slips on the pulley. The tension in the belt is fine just wondering what the next step would be with troubleshooting? Do I have a blockage somewhere?

Also even after filling up the system with refrigerant the cluch still doesn't kick in without jumping the relay.

Many thanks in advance,

Jack.