Sims 4 Glitching and Crashing (MAC Book), help!

Hi! I've had reoccurring problems with my Sims4 account for the couple of days following the latest update. 

At first it was extremely glitchy to the point where I couldn't see my character in the 'build a sim', they just appeared as a silhouette.  

I then deleted the old mods I had on the game. 

Now whenever I load up the game it lags a little bit on the opening screen. Once I load in the family it will be fine for about a minute then the character's/environment's 'skin' will stretch all over the page (Please ref. the attached video) Once it glitches for about half a minute my macbook will crash and close down. Has anyone else had this problem? I recently bought the Realms of Magic add on if this has anything to do with it. 

I have already tried the following: 

- Deleting all mods (and not re-installing) 

- Re downloading the game.

- 'Repairing' the game on Origin

- Moving the 'options' asset from the 'Electronic Arts' folder to the 'desktop' folder

-  Moving the entire 'Sims 4' folder to Desktop so it creates a new folder

- Changing the game graphics (so that the Sim is on 'high' & most of the environment is 'low') 

(I do have Retina display on, the one time I de-selected it the game immediately crashed.) 

If anyone knows any possible way I can fix this I'll be forever grateful! 

Many thanks,

Here's the details for my mac:

Hardware Overview:

  Model Name: MacBook Pro

  Model Identifier: MacBookPro11,5

  Processor Name: Intel Core i7

  Processor Speed: 2.5 GHz

  Number of Processors: 1

  Total Number of Cores: 4

  L2 Cache (per Core): 256 KB

  L3 Cache: 6 MB

  Memory: 16 GB

  Boot ROM Version: MBP114.0184.B00

  SMC Version (system): 2.30f2

  Serial Number (system): C02RM66GG8WP

  Hardware UUID: A399AA25-2760-5BBD-AE67-C6B407DF25CE