Suddenly lost my hotspot connection

Hi, and hope you can help. I care for a senior citizen a few nights a week in a home without internet service, and have been using my HP Presario CQ62 up until now to log onto an xfinitywifi hotspot through my own account. I also have an HP Pavilion I can use, but for some reason that laptop does not have as strong as signal as the Presario and the signal was not reliable. But with the Presario, I have had no problem logging on until now, and the bars in my network listing are usually 4 or 5 strong.
One night recently I lost my connection, and have not been able to log back on since. The xfinitywifi has pretty much disappeared, although it pops up every so often for a moment or two, but only with one bar and also shows being out of range on my android. Most of the other networks usually in the list were gone as well, also just popping up here and there for a moment, and only with one bar. But a new listing appeared at the same time this happened, and seems to be a strong one, with 4 to 5 bars.
One other older network besides the new one seems to remain strong and both are netgear routers. So my assumption is that this new network is somehow sending out signals that, along with the other network, are blocking me from picking up signals.

Knowing a little (and very little) about all this, my fist thought was to change my channel. However, I could not figure out how to change the channel on an internal modem/router (Realtek) in my laptop.
I tried downloading some programs to try and find out what was going on. I didn’t have much luck understanding them, but with one program called Heatmapper I got some info about the other networks. What I did find out was that the new network seems to have less of a mbps reading (whatever that is) than the other netgear that has been there, but never caused any problems.

So my guess is that this new network (and I have no idea where it is coming from) is sending out wifi signals that, along with the other older one, are blocking this house from receiving the xfinitywifi hotspot signals. I did check and the hotspot is still valid.

I did try tethering my phone signal, but it is simply too slow to be able to do anything worthwhile. I am miserable not having my internet while I‘m there through the night, and hope there is a way I can somehow stop the signals from interfering with mine, or do something to my computer that would allow me to again pick up strong signals again to log on, play my games, watch my videos, etc. I do have 2 old routers (a clear express hub and a netgear wnr1000v2 if either could help.

I can’t afford too much, so would appreciate if any solutions were economical.

Thank you so much in advance for your help.