Lets try clearing the cache of your gallery application and force stoping both the gallery and the camera application.
First, go to Settings > Application Setting or Apps
Now go to All > look for Gallery > clear Cache of Gallery
When you have done these things, now you need to press Force Stop button
At last, restart your device and now open the camera app and check if the problem is resolved or not.
After checking that, please do the same for the Camera application and check back in with me to let me know if the symptoms persist.
Have you tried force stopping the camera app and clearing the cache and data?