rear brake caliper problem and e-brake not functioning at all.please help

[240mph]

ok first i just want to start off with my e-brake problem. when i pull up the e-brake it doesnt work at its full potential even if i adjust it from the lever itself. and when i fully bring up the e-brake the rear caliper spring (which connects to the e-brake cable) gets stuck. then i have to take apart the caliper then hit the spring, then the spring will go back to its original place. but the same thing will happen when i pull the e-brake back all the way up again.sometimes one side will get stuck and sometimes both. when i had a friend pull up the e-brake and i was under the car i noticed that when he pulls it up , only one cable retracts and not the other. what is going on with my e-brake do i need to replace the whole cable or is it that spring on the rear caliper which is at fault. somebody please help me out.