Air conditioner Blowing Hot and Cold Air

Coming home from a road trip, the air conditioner went completely hot air.

Stopped and got some R134 Freon/refrigerant. Filled the line and the line and air turned cold for about ten minutes. Immediately back to hot air only.

Did research and was advised to try the horn relay in the M/G CLT (air conditioner relay) to check if bad fuse. Air got cooler. So we used it for the next two days and keeps blowing hot, then getting cool, then hot all in a minute or two time frame. It has been doing this alternating back and forth for days. It works much more consistently in the cooler evenings. Please help.