did i fry my pump?

How did you determined that you had 1/3 of a tank of fresh water in the tank (when the pump started misbehaving)?  Did you go out and visually check the tank (you can see the water level in the tank because the tank is an opaque plastic) or did you read what the gauges indicate?  If you read the fresh water level from the gauge then that is the problem.  None of the gauges are accurate, fresh water, black water, or gray water level indicators.  The drain line from the fresh water tank should be on the bottom front of the tank thus allowing 98% of the water in the tank to go to the water pump. After reviewing your stated symptoms I feel that there just wasn't water in the tank.  Don't rely on the gauges.  Hope this helps. 

How I determined that there was 1/3 of a tank left when the pump started misbehaving is that water continued to come out of the drain for quite a while. Also the guage read1/3

Just run the pump till it begins to suck air Turn it off. Then look at the fresh water tank where the hose suction line is attached. Ignore the little lights.

Is the pump suction line at the water line? If so you have identified the problem, which is that your lights don't give you a proper indication, at least not with the trailer in it's current position. The solution is to continue to ignore the lights and just eyeball the tank level in future.

Also, when the trailer is level, look through the tank at the water line and see where it is in relationship to the supply line and to the gauge electrodes. I have not bothered to do that. I just know from experience that the gauges are not reliable. If you want something more reliable, you would need to go with something like the SeeLeveL by Garnet. It uses external sensors and reads through the tank wall so the sensors do not get fouled.

When I open the fresh water tank drain no water came out even though I had filled it all the way. So I turn the pump on and water came out of the tank drain until it read a third. At that point the pump sounded bad but water kept coming out so I kept running it. I think the pump was out of the water and it was draining naturally at that point although why it didn't drain naturally in the beginning is beyond me