Why does the Wi-Fi connection keep dropping from my iPhone 5S?

My iPhone 5S keeps dropping Internet connection. For some reason, at only 1 location (my house), the Wi-Fi connection keeps dropping off. I will be using the Internet and will suddenly get a message saying "Cellular Data is turned off," and the connection bars at the top of the screen will disappear. When this happens, I go to settings and see that I'm in fact connected to Wi-Fi. This only seems to happen on my iPhone, not my iPad or Mac, and not at any other location, such as other houses or my school. Also, at my house, I can be downstairs in my sitting room (which is where the Wi-Fi box is), in my living room, or in my kitchen for an hour each and have no problem with the iPhone Internet connection. The problem only appears to happen upstairs in my room where I spend most of my time. I have contacted Apple and was told to forget network, which worked, but only for a day (or less). Is the problem the phone, the Wi-Fi, or operator error? If anyone could tell me how to fix this problem, I'd greatly appreciate it.

Tank You!

Get a new router for your room

To make it easier to understand, Wi-Fi works by sending wireless waves in certain radium of area. It's like if it was sound. So it may be something is blocking it in your room. What makes sound lower? Obviously, closing your door, putting something in front of thw speaker, etc.

You have a very low wave frecuency in your room. Try moving some stuff of place of put your modem/router in a higher place or another place close to your room.