Minimalism pays off! During a semester abroad, you shouldn't take everything you own with you – some things can confidently stay at home.
The rule of thumb is: if you don't really need something in the first few months or can easily buy it abroad, leave it at home. You'll quickly realize that traveling with less baggage makes you more flexible and relaxed. In the end, it's more important to have room for new experiences and spontaneous discoveries than to carry around excessive amounts of stuff. You'll probably still buy things locally, which then have to fit into your suitcase for the return journey.
If you do forget something, most problems can be solved easily, either by buying it later or with digital support. Leave copies of important documents with your parents or friends so that they can send them to you digitally in an emergency. If you forget special medication, you can have your doctor send your prescriptions by email to pharmacies in the destination country or, in an emergency, consult a local doctor.