Need some insight with my wireless router in my apartment.

Hey r/networking. I hope im posting in the right place. In my apartment I have my router set up where the coaxial outlet is. My PC is located on the opposite side of the two bedroom apartment. Moving the PC next to the router is unfortunately out of the question, and so is running a long ass ethernet cable across the whole apartment.

So I have to use Wifi on my PC. Currently using a USB Wifi adapter. For a few months, the connection was fine. Lately the download speeds are barely 1 Mbps, No one can understand what I'm saying on Discord, and every multiplayer game has unplayable lag. This is not good. I went from the wifi icon to showing full connectivity to missing one "bar"

So I have a few questions about improving this situation:

1. The router in question is the Comcast issued one that I rent for 10 dollars a month and should probably replace anyway. Can I find a router with better range?

2. In my entirely uneducated opinion, the best option here seems to be put a wifi repeater in the second bedroom and then connect to the PC via ethernet cable. Is this the right way to go about it?

Once again I pretty much have to be on wifi, and also my ISP didnt change anything with my internet speed. Sorry for the wall of text, and I appreciate any input!