This goodbye letter can provide ideas on how to reveal romantic feelings to a long-time crush.
Now that I'm leaving, I think I can finally say something that I'm sure you've known for the last {amount of time}. I'm in love with you. I won't pretend that keeping silent for this long wasn't partially due to cowardice, but I've also known for a long time that you never shared my feelings.
I don't want to make you uncomfortable or awkward, and I don't want you to feel like you have to say anything to me in return. I just wanted you to know that your {personality traits} have always made me admire and respect you. You have been a kind, sympathetic friend, and I've been lucky enough just to have that.
I hope this isn't goodbye forever. I fully expect coffee and an update on your life the next time I'm in town. Don't let my extremely candid confession make it weird between us. You're a marvelous person who deserves to be told how great you are and how much you're loved.
