XPS 15 7590 random shutdowns and boot issues afterwards (urgent)

Hi everyone,

I have a XPS 7590 (june 2019) and since last week I'm facing random shutdowns and reboot issues. The first time it happend I was able to reboot normally, but it happend again very fast. Now I have troubles to get into Windows as my laptop just crashes after 10 seconds booting. First I thought it was some problem with the battery so I removed it and just ran on AC. That worked for one day, but the next day the same problem happend again. Next, I tried to eject and put in the RAM again but this also did not work until I did it again and booted the laptop with the back lid removed. For some reason it is now running in Windows sideways with only the AC plugged in. Can anyone help me with this situation cause I'm finishing my bachelor in computational drug discovery right now and I need my laptop a.s.a.p. 

Hope some of you can help me!

Jelle