You shouldn't have to replace the entire throttle body. If a sensor goes out, usually the check engine light will come on if the ECU monitors it.
The idle raising up and down sounds like it is a loose fast idle thermo valve (FITV). Search the forum for posts about it. It basically is bolted on the bottom of the throttle body and the plunger can get loose over time. Just take it off (with the coolant lines still attached). and tighten the big plastic plunger until it is fully seated.
A quick test would be to plug the lower port in the throttle body with your finger when the engine is running. If the idle smooths out, then you found the problem.
Also, you might want to bleed any air in the coolant system by opening the bleeder screw on top of the thermostat housing.
95 Accord EX MT