Crysis rocket launcher, cant shoot or drop weapon?

So i am at the final boss and the shield is still up. I know im supposed to shoot the turrets with the rocket launchers. Earlier I got frozen by one of the rays and after that i couldnt shoot the rocket launcher i had and it has the appearance of being frozen. So i thought it would thaw out. But that was a long time ago and now i really need it. I have tried to drop, shoot, look through scope but it wont do anything. What should I do?