So, when I build the lighting in my map, it takes friggin forever, like 30 minutes to an hour. And when it finally reaches 100% my pc freezes. I left it for almost an hour and nothing changed. So is there an easier and faster way to build the lighting in my map to fix the weird lighting issues on my walls and to prevent my PC from freezing?
Some more details might be helpful here, like the specs of the machine you’re using to build the lighting, but the complexity of your level and shaders etc matter too.
What quality setting are you using when building? The higher quality settings do take longer than the medium or preview settings and the specific level will make a difference too, as mentioned.
In addition, are you just looking through the viewport to see the result? Are you play testing, and if yes, through the viewport? The standalone client play test will have a better looking result than the viewport play test, took me a little while to realise this initially.
I’ll try reducing the lightmap resolutions to see if that helps. Btw, how do I switch from static lighting to Dynamic Lighting?
My specs: I have a GTX 1050ti, AMD FX 6300, 8 GB of ram and Windows 10. I’m using preview quality when building my lighting. I looked through the view port and the standalone/packaged version of the game and they both look the same, as in, the lighting is messed up, some parts of a wall look brighter than others. That’s why I was trying to build the lighting to fix this issue.
If you are running Windows, and have multiple Windows computers available, you can use Unreal Swarm to offload the process of lighting rebuilds onto many different PCs.
If you have complex geometry or lights that truly are not going to affect the baking, you can put those items on a Sublevel and eyeball off the Sublevel before baking the lighting.
Or you can move from static lighting to dynamic lighting. There are quality and performance tradeoffs, but one benefit will be far faster lighting rebuilds. 
Finally, see the Reducing Build Times portion of the SwarmAgent guide for some general tips that should help you.
Switch lights and/or meshes from Static to Stationary or Movable. The combination of these properties determines what lighting and shadows can be pre-baked versus what must be computed on the fly.