Hello, “Full Name”,
I don’t know if I should be angry or sad or happy or what, your letter is just like a shock to me because we have known each other for years and I have always treated you like my best friend. From the first day in college till today, I have never got any love feelings for you and even you know that. I have shared my feelings for everyone with you and have told you multiple times that what kind of a person am I looking for.
Your letter is very sweet and anyone would be lucky to fall in love with you but its not possible for us to have this because we are friends and after falling in love we will lose our friendship as well and I would never want this to happen. Let us just be friends and even if you want to take a break from me please do take I will not mind that but you will have to move on from this feeling.
I hope you will understand what this friendship means for me.