Hello, thank you for playing the game!
What you're describing sounds like the result of lower affection the first two times you tried to start a route - nothing changes in the Dr. Sharpe conversation depending on affection, but you can only get on a route if your schedule is right and if you've made enough right choices with the patient whose route you chose. I hope that clears things up, because the choice you made differently shouldn't affect anything.
I hope you enjoy the rest of the game <3