Animal Crossing New Leaf suddenly running at 40% speed on MacBook

Issue:
A friend helped me install Citra so I could run ACNL two days ago. Aside from occasionally lagging when walking to a different area (as in, each time I loaded the game it would lag upon entering an area I hadn’t walked towards since opening it for that session, if that makes sense?), but that was completely fine by my standards, and didn’t persist for the full session anyways. I found that my laptop’s fan went into jet engine mode if I ran Citra and some other application at the same time, eg Citra and chrome, but y’know, MacBook.
Other than minor performance issues, it was pretty much fine, ran at 60fps and 100% speed. That was until I think halfway through yesterday, I was playing it in english class and so had to occasionally keep closing it (after saving of course) and quitting the application so I could go back to using chrome (I believe I did have chrome open some of the time while running Citra in class). All of a sudden, I think halfway through playing the game, when I exited my tent (I think it was when I did that), it dropped to 40% speed.
I have not been able to fix this since, and my friend has been too busy to help me out so I’ve come to these forums. Even when I don’t have a single other application open, not even Sticky Notes, the speed has not peaked above 40%.
Highly worth noting: I am an idiot. I am not tech savy. If you have solutions, please dumb it down for me, I’ve tried looking at other posts with similar issues and I didn’t understand a thing. I am very sorry for making y’all deal with my uneducated bs.
Thank you in advance, I hope I submitted everything correctly

System Information

  • Operating System: macOS
    (I’m really not tech savy at all so I’m not sure what the CPU or GPU is but going by system information found in “About this Mac”, my processor is 1.6 GHz Dual-Core Intel Core i5, memory is 8 GB 2133 MHz LPDDR3 and graphics is Intel UHD Graphics 617 1536 MB. I apologise for the inconvenience)
  • Citra Version: 1628 nightly
  • Game: Animal Crossing: New Leaf
  • Screenshot of Issue (include the full Citra window including titlebar):

Diagnostic Log
citra_log.txt (13.5 KB)

System Information for Support

Client Version                                Nightly 1628 HEAD-1c8461f
Operating System                              macOS 10.15
CPU                                           Intel(R) Core(TM) i5-8210Y CPU @ 1.60GHz
Graphics API                                  OpenGL ?
Graphics Renderer                             Intel(R) UHD Graphics 617
CPU JIT                                       [x]
Hardware Renderer                             [x]
Hardware Shader                               [x]
Hardware Shader, Accurate Multiplication      [ ]
Shader JIT                                    [x]
System Region                                 -1
Shader Disk Cache                             [x]

Here’s some issues I found with your log that might help.

  • Enabling Accurate Multiplication is recomended in certain games. If you are experiencing graphical glitches, try enabling this option.
  • You are using open source system files for Mii data. This will appear as your Mii having broken graphics, but will not affect the stability of the game. In order to resolve this, please refer to our guide on dumping system files. https://citra-emu.org/wiki/dumping-system-archives-and-the-shared-fonts-from-a-3ds-console/