There are plenty of students who are uncertain about what they want to study at uni, or whether they want to study at uni, or what they are interested in as a career. There will be plenty of students who change directions in the first semester / year of uni studies - transfers happen both to move to more desired degrees or because the realisation has happened that the degree isn't really what they expected or truly want. You are far from alone.
Your feelings of being a disappointment or even a failure are arising from a distorted self-image, distorted by your feelings of depression. The overwhelming majority of students will not get 95+, so on any objective basis your school performance is laudable. Sadly, having feelings like this is also far from unique to you, there are many struggling with mental health difficulties, which are actually more common amongst those with accomplishments at the high end of intellectual achievement.
Please be aware that there are people around who only feel positive about themselves when they are pulling others down. Try not buy in when they make comments that are meant to minimise you and your achievements. They can do great harm by denying the idea that mutual support assists everyone to rise. As a social species, we do better collectively and individually by contributing to and being supported by others in line with our capabilities at any given time. I applaud you for reaching out, and am glad to see contributions to this thread who offer support and suggestions as they see fit.
I agree that focusing on your exams is the wise course at the present, and offer my experience that decisions like selecting a degree course are neither irrevocable nor should they define your future. You have the power to choose your future, and even a journey with some wrong steps c an be fulfilling and worthwhile. Finally, those self-doubts and pseudo insights that are coming from your feelings of depression, your great challenge is to learn to recognise where they are coming from and how they are distorted so that you can choose your actions appropriately. Good luck in the exams!