Premiere Pro taking up all available memory, timeline won't play, freezing, crashing

[lachland13108572]

I have updated to Premiere Pro 15 and there are A LOT of problems. 
- Timeline will not play the majority of the time
- Jumpy playback BUT ALSO the same jumpy export - when the timeline did play a few days ago. Now it won't play at all. 
- As soon as I open up a blank project file the availalble memory goes to 0, CPU usage maxed out
- Crashes and says 'there is a major error' etc

I have a Macbook Pro 15'' 2016, 2.7 GHz Intel Core i7 16 GB 2133 MHz LPDDR3. I use other heavy CPU programs such as Abeton Live with no issues whatsoever. At a complete loss