I might have finally found the dress! Thank you for all the suggestions, they were really helpful! I looked at the sites and definitely found cute dresses but they were either too short or a little bit too sexy. I looked at a lot of webshops and sometimes the amount of dresses can be overwhelming as well. I did see this dress before at the C & A webshop but it was sold out in my size. Now it was back and since they were no forwarding charges and to be honest, I was getting quite desperate, I ordered it.
This dress is € 49,90 euros. I hope it looks cute and fits correctly!