Dear Lost Vagabond,
If there’s one thing I’ve learned from my friendship with Harry and Ron, it is that grades are not always the best indicator of intelligence. However, they are often important, and should therefore not be ignored. Keep working your hardest. Communicate with your professors (they are always more than happy to help, especially students who care enough about their education to ask for assistance!) Really commit yourself to learning, more than getting a higher mark.
As to how to find yourself, start by finding something you love and are passionate about. It may take some time to find that, and you may have to stretch out of your comfort zone to do so. Once you’ve found that, find where you want to take it, and then work for it! Most of all, never worry about what other people may say about your passion. If it makes you feel happy and fulfilled, then you should pursue it.