This is common. Any coming future you are unsure of will make you feel anxious. You know you can succeed in college because you have experienced it but you don't know if you can succeed in the workplace as you have not experienced it. You may be a more generally anxious person like me. I graduated top of class from my small state college and was super anxious about going to a well known grad school.
I've learned a few lessons since then. The best advice I can give is this: (1) Be committed to practicing thankfulness and contentment and (2) be committed to adapting and learning in whatever situation you face.
If you know that you can still recognize the good things about your future work situation and come from a place of humility instead of entitlement (which is easy to do even when you aren't a jerk) you will be more at peace with the future. Be thankful for the success you've had in college. Grow amazement of the possibility of things still going well.
And if you are committed to being flexible and finding solutions to things that aren't working out as well as you'd like, you will be more at peace with the future knowing that you have some power to improve things. You aren't going to know everything you need to know for you job. But if you know you can learn, that is enough.