Random app crashes on MBP running Sierra

Hi all!

I have a difficult question: I am using a MacBook Pro (Retina, 13-inch, Early 2015) running MacOS Sierra10.12.6 (16G1212). Every once in a while this computer either stops completely (screen and apps in tact, but touchpad doesn't click, mouse doesn't move, keyboard cannot be used). The only thing i can do is power off and restart and then the computer always reboots correctly. This happens at least once every two or three days.

Another issue i have is that quite randomly apps stop. Mostly when TimeMachine is working, but also when it's not. Mostly it's either Chrome or Outlook which stop, but that might be because those apps are always open. Many other apps also stop randomly, even the Finder shows me a spinning ball forever. Command line tools never stop.

I use this computer for work appx. 14 hours per day every day.

How can i diagnose what is happening? I am getting to the point where i will buy a new laptop, but if i can troubleshoot and fix this problem, that would save me a lot of time compared to purchasing and installing a completely new laptop.

Any suggestions are greatly appreciated.

Ton.