Help with slow home internet

I recently moved into my first house and I decided to get the T-Mobile home internet gateway as that seemed to be the best of the few options I have. It’s also what my parents have and they have very good internet considering our location. I live approximately 15 minutes from my parents in a rural area and I just cannot seem to get any decent signal. I like to play video games and my computer is currently downloading a game at 1-2 mbps or less. It’s also worth mentioning that I get excellent service on my Verizon cell phone at my house so it’s not a complete dead zone. And yes I have moved the gateway all around my house to find the best signal. I can get 3 bars on it but that’s the most I’ve seen, it usually is either good or weak signal. I have read some threads on here but quite honestly I am not up to speed with this type of stuff. I was hoping y’all could maybe dumb it down for somebody that’s not tech savvy or help walk me through anything I could do to help my situation. I’ve also tried to call T-Mobile directly to get some help with solutions but could not get any answers. Thank y’all in advance.