can cause high pressure reading and obviously no cold air.

A/c work is a pain. You need gauges for both high and low side ports. If an expansion valve is the trouble the system will have to be opened (should be evacuated, releasing r134a is not legal), the dryer will also need to be replaced after the work is done and the system has to be vacuum pumped to remove water from the system and confirm no leaks before it can be filled with refridgerant.

First check all electrical components, fuses, fans, clutch, switches and so on.

It takes a fair amount of equipment to do the job yourself. Often worth having it done by someone else.

You can rent the gauges for both ports at a auto parts store for free and with a thorough check of electronics figure out what the problem is.

Good luck. Youtube or reading repair protocols will help.