So, as Churchill said of UK and USA, "we are sister nations separated by a common language"... I assume you are on the Ground Floor (floor 1 in USA) and the cable arrives on the floor just above you (floor 2 in USA but first one above ground level). (In UK, it's ground floor = 0 / first floor = the first above ground level).
Obviously, the very best would be to have someone pull some form of cable (Ethernet?) from your computer to the arrival router. (Even if it runs on the staircase wall, no need to drill through the building.) It depends how the arrival router is made but it should have an Ethernet "RJ45" plug.
Second, would be to have the cable company move the arrival point. (Probably over-billed intervention though.)
But if you can't do that ATM (especially if the WiFi is shared in the building)... well... there is not much that can be done but it still may work (but the building structure may cause issues too).
1) check your WiFI antennas: how is WiFi on your computer? Do you have an antenna? If it's from the motherboard directly, chances are the transmission is weak.
2) Move your antennas, get closer to the router spot... like in the old times when people moved radio sets to "catch the station".
Those two things should nevertheless
be attempted on BOTH sides: computer and arrival router.
3) There are WiFi boosters / Repeaters on the market but it's going to cost you more than a proper cable install, without any guarantee. (And what side needs to be boosted? Computer? Router? Both?!)
Check this article (but check many vendors if you go that way, for reasonable prices)
WiFi Boosters, Repeaters and Extenders
https://www.repeaterstore.com/pages/wif ... ifferences
4) Get better WiFi equipment: once again MUCH more expensive than a cable connection and no guarantee at all. (Actually, it's impossible to say without knowing the exact situation if a repeater isn't better than a new equipment.)
5) Change Your WiFi Channel: this is not always possible, depends on the arrival router (and you likely need access to it, so....
Check this generic article for 5) and other tips:
How to Fix Wi-Fi Lag [optimistic title]
http://classroom.synonym.com/fix-wifi-lag-21286.html
Now if you feel like a techie, you can actually measure the strength of the WiFI signal. But in both cases below, you have to move in your home which is maybe not much possible as you are still recovering.
Bottom line: try to look for a physical connection solution. Check also with anyone managing the Internet if it's a shared (in a way or another) WiFi; maybe they can do something.
If it's a building-shared WiFi, let me know.