Re: lost photos and videos
Welcome to Android Central! So you're certain they were there before connecting the phone to the TV, or was that just when you realized they weren't there? How does the TV interface with the phone? Is it supposed to read the directories? It might not be able to read from a phone correctly, since it might be intended for use with USB flash drives only.
Do you know if the photos and videos were being saved to Internal Storage or directly to an external microSD card? Try installing a file manager app like ES File Explorer, and look in the /DCIM/Camera folders in Internal Storage and the external SD card.