I think it’s a good exercise… for you. It’s clearly not for everyone and I would hesitate quite a bit before actually giving them to anybody. Even your wife if and when you marry as you said, “ten years from now.” I find it to be more a form of journaling and that’s not an unmasculine thing. Most of our greatest men have kept diaries or written volumes of both professional and personal letters.
My only caution would be this: Remember that you are not merely trying to be the best person you can in order to provide for a wife and a family. It needs to be for the glory of God. I say that because I too used the whole “if I have sex with this woman, I’ve cheated on my wife before I met her” or “I need to do X, Y, Z in order to be ready” thing in order to remain a virgin and prosper through most of college.
When I started dating my wife in my senior year, I kind of projected my entire sense of being onto her. She became almost my god, which is really weird. I kept that to myself but a lot of what I wrote to her (in letters that were to specifically her and not written earlier) about her being my source of inspiration was not hyperbole. The sonnets and letters were all real feelings, and over the top feelings to be honest.
Women are not goddesses to be worshiped and while I’m sure you’re quite aware of that, I caution you about going too over the top. Excel in your studies for the glory of God. Remain chaste for His glory and your own soul. Tell Him your fears, anxieties and your hopes and dreams as opposed to a woman who you don’t know.
I like that you’re keeping your “eyes on the prize” so to speak, but remember that she is not your ultimate goal. Heaven is. And the only way you’re going to deliver on your responsibilities of helping your future wife and children get to Heaven is to remember where your eyes should ultimately be turned.