Well he is your pharmacist and nothing more. You're basically pouring out your heart to someone that you have no personal relationship with, just a professional one. Plus calling him handsome implies that you are possibly interested romantically and that is very forward for someone who just gives you medication. I wouldn't be surprised if this letter actually made him feel uncomfortable.

You have a habit of pushing boundaries with people and I worry that you may end up doing the same with this pharmacist.