Falling in blackness is how my WILDs start. It used to bother me but not anymore. You want to use dream control to exit, but I think the hurdle is that the feelings of struggle and panic make attempts at dream control just desperation, and thus ineffective.

So I think the first adjustment to make is to reframe the situation in the positive. You became lucid! Congratulate yourself for that and allow yourself to be happy and excited for that, regardless of the scene. Then, don't try too hard to escape the void. I've come to find it quite pleasant, falling with a nice breeze of wind. I think the panic comes either from the sensation of great speed or the fear of being lost. Reframe that. You aren't going anywhere fast and you aren't lost because there's no where else to go in a void. You're right where you are and it's a familiar place. That was the trick for me: to be calm and content in the void because I know there's no danger. Once I achieve that calm, then I am better able to exercise control. I can stay in the void if I like. Or when I want, I visualize a scene below me and gently fall and land on it with the ease of Superman. It's not an attempt to escape. Falling becomes a transition to a new scene.