Hello
JessicaOn4k. I unfortunately have no suggestions to resolve your potential water block issues. Although I will ask you if your GPU is the ASUS GeForce GTX 1080 8GB Turbo. To my knowledge, that card has a AIB "reference cooler on it. I personally used to have the EVGA GTX 980 Ti SC reference cards, and the stock fan curve would have the cards at a constant 84C, per design.
Even though I don't have an answer to your direct question, I did want to offer advice on what you might do to hold yourself over while troubleshooting your GPU problems.
If it were me: I would definitely create a Nvidia Geforce NOW account. GeForce NOW connects to digital PC game stores so you can stream your own library of games. While some game launchers aren't compatible with the platform (e.g. Riot, Blizzard Activision), there are many games that are:
https://www.nvidia.com/en-us/geforce-now/games/
There is a paid account (~$10) as well as a free one. The one major caveat is that you must have solid internet for this to work well. If memory serves, I believe 25 mbps downstream is the minimum requirement, but 50 mbps is recommended. Also, wired Ehternet connection is preferred, followed by 5 GHz wi-fi, with 2.4 GHz being the least optimal connectivity for the service. Also, the service is limited to 1080p 60 Hz gameplay, unless you pay for the premium $20 a month service, that provides RTX 3080 service with up-to 1440p 120 Hz. I've been playing on this service since it was first introduced in beta, many years ago, and it's honestly very good. For now, consider creating a free account tonight and see if it fulfills your needs. The free account has the performance of an RTX 2080 Super, so you should be pleased with the performance, if you can live with the 1080p 60 FPS limitation.
Also, down the road, you might consider a platform upgrade: Normally upgrading from a core i3-6100 to a core i7-6700K would be a logical upgrade, except that particular i7 chip costs $200 used on Ebay right now, but has the performance of a modern $100 CPU (e.g. ryzen 3 3100 or intel i3-10100). Don't buy either of those examples I just referenced. On a super tight budget I'd try to find a used (w/ BIOS already updated) B450 chipset motherboard from a friend or fellow gamer <$60), and possibly an open box Ryzen 5 3600 which I see selling on Ebay US for $180.
Sorry for all your PC problems. Sounds like a nightmare.