1. REBOOT your iPHONE - seriously.
2. Unplug, the replug iPhone into PC.
3. If no DCIM folder in iPHONE device, take a new picture - seriously.
4. Close "This PC", then re-open it, then click on iPhone again.
5. Wait a few minutes while it is connected for "Internal Storage" folder to appear
6. Turn off Passcodes completely.
7. Turn Autolock off (to Never).
8. Make sure phone is unlocked.
9. Try a different PC.
10. Stop Using iPhones and get an Android.
You want to clear up some space on your iPhone:
In DCIM, you can't delete directories, but go inside each DCIM folder, select the files you want to delete, and delete them there.