A few questions came to mind based on what you're describing. Can you physically see both the fans moving when the engine is running and can you freely move them with your hand when the car is off? Have you checked what your oil looks like recently, that would likely be the best way to identify if you have a cracked block at this point without tearing everything apart. I suspect that when you replaced the thermostat you had to add coolant/flush the coolant, what did it look like before hand (color, etc.)?
The fact that you've been driving it with this issue for 8 months suggests that if any thing seem out of the ordinary with the above you may have already damaged the engine.
95 Integra LS - Touge/Time Attack