ترجمه - سوئدی-آلمانی - Rummen jag spenderar mest tid i är i mitt rum,...

The context could demand "in den ich ... investiere" but without knowing I would prefer "Der Raum in dem ich die meiste Zeit verbringe ...".

In English the difference would be "the room I spend must time in/on" (on=investieren, in=verbringen)

I think Zimmer is better than Raum in German, since it's rooms in a house.