My fuel meter in my dashboard goes up and down.

Fuses are not intermittent. When they blow, they're done. They don't magically fix themselves. Also, there is no separate fuse for just the gas gauge. A blown fuse would affect many things on the dash.

With the consistent symptom you described, that is typically of a defective sending unit in the gas tank. Chrysler had a similar problem that took less than ten seconds to fix, ... Once the unit was out of the tank. I suspect yours can be fixed too but I never did one on a GM product. If it is riveted together you'll have to replace it.