I dropped out a year and a half ago, but haven't told anyone. I've kept it a secret.
Why is this a secret exactly?
I was just so ashamed of it.
This is your life to live, nobody else's. If you felt dropping out was best for you, there's no need to feel shame.
Yeah right. What if I didn't and went through with everything?
There's no need to think about the 'what ifs'  in this situation. All that matter is the present moment, so don't worry anymore.