Simply replace the unfilled areas such as "" and "[date]" with your information.
Although we haven't yet met in person, I can't help but feel that I know you better than I have ever known anyone. From our very first [exchange], there was some kind of spark. Even though we were only writing about [subject], I could tell that you were someone of deep [adjective], [additional adjective], and inner beauty. I find myself checking my inbox too often. I can't help it. You have become a light in my life. A day without your messages is like a day without sun.
There is no other word for it but love. There are many people out there who may not believe love can happen online, but I promise you it has. I now think that this is the best way to fall in love. Falling in love with one's soul first is so powerful. It is so much more than the love that develops from trivial surface qualities and then quickly fades once one looks more deeply. Please know that I love you with a very deep, honest love.
Thinking of you fills me with [noun] and I can't wait until your next [message type].