Welcome Wouter,
You have no idea how familiar that all sounds.
During my flight Training sometimes I couldn’t even sleep.
That was more then 25 years and 11,000 hrs ago.
Its perfectly normal, you’ve started a major new chapter in your life.
Flying is very stressful enterprise this early on because it’s all things you haven’t dealt with before and it’s such a cacophony of sounds.
Movement in all axis with a new component, up and down, that you’re not used to.
Loud engine, somebody trying to talk to you and you trying to make sense between whatever he told you in the classroom.
Enjoy your flight training!