An Extremely Annoying Wi-Fi Issue

We all know about the little Wi-Fi icon at the bottom right of our screens, but mine is only showing a dot where the full icon should be. When I'm done using my laptop for a while I close the lid. Often times when I open it again it shows that I have no internet. I have to manually connect it to the network with the password every time. We have two laptops in our apartment. The modem is set up behind my mother's chair so her laptop is really close to it and it works fine. Mine is in a room around 20 feet away and there are walls and her chair in the way so I can understand why it can interfere with things.

As a test, I brought my laptop into where hers is and my Wi-Fi icon appeared in full. When I brought it back into my room the icon went back to just a dot, but what confuses me is that if I bring her laptop into my room the icon and connection works just fine. Her laptop is new, mine is two years old. Below are the issues I'm having:

1. Having to connect my laptop manually to the network whenever I go to use it after around 20 minutes of inactivity and even then the Wi-Fi once connected is weak.
2. Pages sometimes take forever to load.
3. Sometimes my Youtube videos lag, taking a long time to buffer.