The A/C system only works when it is cranked all the way up to five on the fan dial

So, we could have a couple issues. First, when you say it only works when it is on level 5 does that mean the fan doesn't blow unless it is on high.

If that is the case, then you have an issue with the blower motor resistor.

This is typical when they fail.

https://www.2carpros.com/articles/low-or-no-air-flow-from-vents

However, as for the Freon level and it is blowing hot, that is going to be a different issue. It sounds like the compressor is not coming on but at this point we have the system over filled.

So that means we are going to have to evacuate it and charge it properly. Here is a guide that will tell you how to do that:

https://www.2carpros.com/articles/re-charge-an-air-conditioner-system

Then we will need to check the compressor operation as the freon level being too high can cause it to cut off, but it more than likely has failed.

We will just need to find out what the pressures are when we charge it and that will tell us what is happening. I am attaching a chart below that will help with this.

Let me know what you find, and we can go from there.

Thanks