Ford Escort doesn't blow hot air but shows it overheats

I recently bought a 2000 Ford Escort ZX2 and replaced the timing belt and tensioner, the water pump, the
thermostat housing, thermostat, both temperature sensors, the fan, and the ignition coil pack. After doing all of
this work I got code P0118: "Engine Coolant Temperature (ECT) Sensor Circuit High Open Problem" (I
remember one of the sensors clicking different than the other one and I'm wondering if that has to do with the
code). I didn't flush the system because after running the car for 20 mins on idle I had heat. I lost it 2 days later.

The Escort runs really rough when it is cold and misfires when I take off but I don't get a code for any kind of
misfiring (not even random misfiring). After driving for a couple minutes the temp guage on the dash goes from
below "C" to basically pegging at hot then bounces/fluctuates between halfway/normal and hot ("H"). I haven't
driven it for a couple days because I don't want to assume that the engine isn't getting as hot as it claims.

Any help or suggestions would be appreciated, I've already put way more time and money into this car than I
wanted to and than it may be worth.

If you want, I took a video of the fluctuating temp guage that I can try to post or even give a link to.

Thanks