Engine Noise

I have a 99 nissan altima. This car used to be fine when I bought it.
after 3 months a hose started leaking and the antifreeze also started leaking, after fixing that problem and also replacing other parts such as the water pump and head gasket, the engine started making a grinding/ratting noise and the temperature gauge starts going all over the place,
the car does not overheat or anything but just to make sure I got the thermostat changed, and that didn't work.
The oil and Check engine light are on.
Right now the engine makes a grinding/clicking/ noises, its so loud that everyone turns around to see what's happening with my car.I don't know what to do.I can't spend more money on this car. Could anyone tell me what could be wrong with my car. Any help is appreciated