Alright, as is typical with nearly every problem I have, I fix it the moment I post the question. For anyone else having a similar issue, evidently mine was caused by having multiple devices on different bands. The Chromecast was on 2.4Ghz and my computer/phone were on 5Ghz. That's why my phone could see the computer but not the Chromecast. Now why my computer could still see the Chromecast, I have no idea. I changed my phone to the 2.4Ghz, so suddenly I was able to see the Chromecast but not the computer. Changed EVERYTHING to 2.4Ghz, and it's all working fine now. I hate networking =/