My hot tub turned off. When I reset the breaker, it displays 8888 for a second and then goes off. This continues and we have no power.

So you mean the LCD on the tub reads 8888,right? You need to check with the owners manual or manufacturer to see what the code means. My wild guess is a short in the circuit board of the tub trips the GFCI, when you reset the breaker the tub can't clear the fault.

Without knowing the brand and model of the spa, all anyone can do is make wild guesses.