Professional help
If your mental health is affected, you can seek help within your university. They provide counselling, psychological help as well as other support. It is possible to get in contact with the several type of help online and schedule appointments. You will get the help you need and might get information on further steps you can take like finding a therapist for example.
We hope to help you with our suggestions in times you might feel lonely. Try to find something you like and you will hopefully meet nice people that way. Find ideas for indoor activities in Nijmegen on our blog.