Need genuine advice!!

Please read it!! Hi everyone, I’m from Ontario and very interested in pursuing dentistry, but I keep hearing how extremely competitive dental school is in Canada and it honestly worries me. I wasn’t always a strong academic student. I was average to below average in earlier grades, but in Grade 10 I decided I wanted to pursue dentistry and started taking school much more seriously. Since then, my work ethic has completely changed. In Grade 11, I raised my average from the 70s to the 90s, and now in Grade 12 I’m trying to maintain that while taking a heavy science and math course load. I’ve been accepted into a few Health Sciences programs and I’m genuinely passionate about dentistry, but I keep hearing that one bad grade can ruin your chances and that undergrad is extremely difficult. How true is this? Is it realistic to stay competitive if you’re hardworking but not naturally gifted? I would really appreciate advice or experiences, especially from Canadian dental students or applicants. I’m sorry, but im posting here because Reddit keeps removing my posts on predent subreddit. 😭