English-speaking intern searching for a 6-month accommodation in Dortmund

I am a 22 years old French student in a Master equivalent of molecular biology in a French University called AgroParisTech. I will be doing a 6-month internship starting in November in the Institute for Virology and Microbiology, at the Witten-Herdecke University. Thus I am searching for an accommodation in Dortmund, preferably near the S5 line, or in Witten directly.

Personally, I am a calm-minded, very curious, and open-minded person, and I am quite fluent in English (sadly not in German). On my free time, I like to watch all sorts of movies and do a lot of model building and miniature painting as a hobby. It is quite uncommon for sure, but it helps me express my creativity and the advantage is that it's a fairly quiet activity ! When the weather allows it, I love to venture outside with my friends to discover the local history and gastronomy.

My parents will financially support me, with the addition of my personal savings. SCHUFA (jetzt beantragen) rating can be provided on demand.