HELP! I made a mistake when sculpting and when trying to fix it, it lead to a bigger problem (Pictures included to help get my point across :) )

I was sculpting this character that I've been working on 

and I made a classic blunder. When I was sculpting the ear i accidentally forgot to turn the symmetry on. Because it was almost finished and I hated sculpting ears, I decided to try to work around it

I used the Boolean Modifier to cut the sculpt in half and then mirrored it. Everything seemed fine until I realized that because of this, there was now a face/mesh in the middle inside of the sculpt 

Now whenever i sculpt this happens.


I tried manually deleting the mesh inside using edit mode but because of the bad topology from 'dynamic topology', its nearly impossible.


I really need help! I want to finish this sculpt.

Here's the blender file: blender file

Thanks a lot guys!
There seems to be an easy fix for your particular mesh problem: (because it is a nice flat internal surface)


Go into front view and turn off perspective (press 1 and then 5 on Numpad, ... or tick emulate numpad in the preferences menu if you don't have one, in that case also 1, 5)
Its always very important to see what is going wrong without all the rest blocking the view, so then use Alt+B to box-restrict the visible mesh around the center:
Then select one of the internal faces and select "linked flat faces" (shortcut: shift+ctrl+alt+F)
then delete those with ->delete->Faces and check if this solved the problem. As you can see in the right picture in your particular case the mesh is already clean after this.

Now you can use Alt+B again to return to the normal unrestricted view.


That should have done it! Happy blending! :)