Replying to Student Wifi is garbage

So in my dorms there is a universal wifi network for all students to use. I'm not sure if there are multiple routers and whatnot but, I have a fine signal. like anywhere from 3-5 bars. I'm having a hell of a time receiving an internet signal for anywhere longer than 2 minutes. Every 2 minutes or so a yellow exclamation point pops up on my bars (still connected) and says "Limited: No internet access". I have to disconnect from the network and reconnect only to have the same thing happen in 30 seconds-2 minutes. I've contacted tech support and the guy says they put better antennas on and I am still having the same exact problem. Unfortunately there is no ethernet in my room but there is a phone jack.... This has been irritating me to no end and I can't figure out what to do. Would there be a way to create my own signal somehow? I see there are other wifi networks obviously not ran by the school such as "GET YOUR OWN WIFI". I can't use anything that connects to 3g/4g as I am in a town that does not get either of those.. This has really been irritating me.... Anyone that can help solve this problem gets +K and I will send some stickers.