So my brakes recently have been going out,they seem almost spongy..When i press down on them at medium pressure they most of the time brake as theyre supposed to but sometimes they brake really hard suddenly.Also once my 4runner is coming to a stop or the last two seconds of braking it makes a click click click click click sound untill my wheels are completely stopped.

 

Not sure about all you problems but for me the click click click was the dust shield hitting the rotor up front. Bent it back and the noise went away.

For the rest of your problems, not quite sure, but if you did any recent brake work maybe the system needs to be bled better. Or if haven't done any work maybe you have moisture in the brake fluid and need to flush the system.

 

clicking noise is usually the dust sheild, but sometimes the wear indicators when they have dug too far into the rotor, or have worn down far, they click cuz they dont always touch the rotor. if thats the case, you need to pads and rotors.

 

Pull a wheel and inspect. Check the dust shield, pads, and rotor condition. The sponginess is probably air in the line so they need to be bled for that issue.

 

Two possibilities:
Master cylinder is going, or much worse, and less likely, the vacuum boster is going bad.