I got a serious problem with my foot brake, and I noticed it when I got stuck mid-way up a steep hillclimb. Luckly- I made it down with out rolling... but here's the problem

When I press the brake lever down... it stays down and doesn't return back up. I have to manually lift back up. When I wiggle it by hand... it feels really stiff and sticky. When I press it to the max... It doesn't lock the back wheels as tight as it used to. The brake fluid is fine.

Anyone got any ideas on what's wrong? This happened after rolling my 4-wheeler... but I can't see any physicial damage to either the brake calipers or the actual foot brake.

thanks for the input...