I understand that awaiting a visa decision can be nerve-wracking, but at this point, there is nothing you can do. All you have to do is to wait patiently for a decision. The German Embassy looks at each case differently. The fact that your friends got their visas approved within a short time frame doesn't necessarily mean you visa will also be approved within the same time frame.
The German Immigration Offices will take a minimum of 4 weeks but might take 8 to 12 weeks for processing your visa application. Therefore your 54 days is still within the time frame that the German Embassy takes to process student visas.
If you haven't heard anything by the1st of June, you can send the Embassy an email to inquire about the status of your visa application. However, you should note that the Embassy does not influence the actual processing time.
You can also ask your university if it is possible to extend the enrollment deadline for your language course again if you still haven't heard anything by the 6th of June. Hopefully, you hear something positive within the week.