Electric Shower Dripping What Is Going On With My Water Heater Tank?

What is going on with my water heater tank? - electric shower dripping

I bought new from Home Depot. I hired someone (I do not know who did it) to install it for me. That was about 5 years ago. Now, only the last two months I have noticed that the hot water in the shower not long hot (the rest of the house seems very good for hot water). I heard a drop of water in the garage, where you installed the hot water tank. The water comes from leaks PVC pipe connected to a tank top and just hung there. It seems that if I drop heat (from the normal account to save power) and take a shower. I did not even know what the tube. Any way to fix it on my?