I have a 1999 Honda Accord. The AC Fan stopped

This will be 2 separate problems.
The blower motor operating only on high speed can be fixed by replacing the blower motor resistor.

There are several reasons why your A/C is not getting cold. The most probable cause is that there is a leak in the system and the freon has leaked out. The size of the leak and where it is leaking from can vary immensely, as will the cost of repair. You might get away with just a recharge for a while, but that will not FIX the problem...it will definately do it again if the problem is not repaired properly. A small leak, costing $150 to repair right now, could easily end up costing $1500 or more if not fixed properly.