Its never too late. Your mindset makes you who you are. If you are 'thinking' you wont get into it then i guarantee you wont get into it. The day you start owning up to urself, you wont need validation.
you should be able to say "I will study hard, and I will get into med school so what if I did bad? I'll learn from my mistakes"
This is the mindset we aiming for here, if u dont develop this there will be a point when you might end up losing everything.
Work on it.