Hello everyone

After many years of working, im starting a saturday school to educate myself further. It takes 6 months and i will receiving a diploma for it. 
The problem is that im a pretty shy person and going to a school with people i dont know scares me.
I always struggled with school, while work (for some reason) was never a problem for me.
Just the thought of going to this school scares me so much that i went sick from all the inner stress i get from it. At the same time i really want to get the diploma to make things easier in my future life, so just cancel it because of the anxiety is no option.

Does anyone have the same problem/experience with this specific topic and know some tips to manage this situation?

Thanks.