Black lines appearing across screen 2016 MBP

This is a problem I've been having for a while now, maybe a year and a half since I bought it.

I should first clarify that these lines only appear to certain conditions. Here's the rundown:

1. Whenever I'm doing something that causes the computer to get really hot, like playing a game, or, most times, running OBS, the lines appear to the bottom. Anything taxing on the processor. Regular programs like Chrome alone don't make it overheat. Watching videos on Netflix a little. Besides that, nothing more.
2. I often hear the fan a little loudly but it doesn't seem to be helping. I've found that whenever I'm in an air-conditioned room for a long time, then turn on the computer and open a game, the lines don't appear as much, or nearly not at all. But when I'm in a room withoutAC, the lines appear quickly. Clearly it's a cooling issue.
3. The previous place I lived at had amazing ventilation, but was always filled with dust blowing through the house. I think this may have caused a dust build up in my laptop, and that may be contributing, but I'm not sure.
4. Finally, black lines don't just appear and causes a nuisance, if it gets bad enough, and is going on for long enough, it's kind of like the lines burn into the monitor, and even after I change screen, you can still see what was previously displayed. For exampled, in the screenshot above, my desktop background is blue, and has the edge of a triangle to the lower left. When I move over to a blank screen on Chrome, you're seeing that triangle, and when the screen is black, you can see the blue of my desktop on the bottom. This is only solved by shutting down, and letting the laptop cool down and rest for like an hour to three hours. When I get back, it's gone.
5. Also, a few of the keys on my keyboard are a little wonky and need to be pressed extra hard for them to work, or pressing one key gives two of it. I also think this is dust build up.

SOME HISTORY FOR CONTEXT

1. A while back i splashed some water on my monitor but I cleaned it off. That water did trickle to the bottom of the screen though. I don't know if this contributed.

Is there anyone who might have an idea of how to help? I'd like to see if there's anything more I can do before going to the genius bar. I'm on a 2016 MBP 13 inch 4 Thunderbolt 3 ports, running Mojave 10.14.5