Objects are transparent from certain angles So i've been editing a few models and at random times the model would become see through depending on the angle i was at. Both in Edit and Object mode.

If i go to Compositing it stops.

For example if i look head on at a character head i can see the inside o fthe back of the head, the front appears to be in wireframe mode.

Then if i rotate the camera to be at the back of the head, i can see the inside of the face.

I think i hit a shortcut but i'm not sure
Based on the description of your situation, you might have inverted the normal of your mesh object.

Go into mesh edit mode.  Select the entire head/or everything, go to mesh menu, select Normals option, select Recalculate Outside option.