Citing the encyclopedia to describe love is like reading a dictionary to find out what the color red is. You'll get a technically correct definition, but it doesn't necessarily help with practical understanding.

I like the way Elizabeth Barrett Browning put it:

When our two souls stand up erect and strong, Face to face, silent, drawing nigh and nigher, Until the lengthening wings break into fire At either curvëd point,—what bitter wrong Can the earth do to us, that we should not long Be here contented? Think! In mounting higher, The angels would press on us and aspire To drop some golden orb of perfect song Into our deep, dear silence. Let us stay Rather on earth, Belovëd,—where the unfit Contrarious moods of men recoil away And isolate pure spirits, and permit A place to stand and love in for a day, With darkness and the death-hour rounding it.

• Sonnets from the Portuguese XXII

You may have loved her, in the sense that you felt affection toward her and wanted good things for her. Good friends, I would argue, should love one another in that way.

But this need to "confess" your feelings, seemingly out of the blue, after a long time apart, is not indicative of simple friendly, platonic love. This sort of "puppy love," as we might refer to a youthful romantic interest or infatuation, is different from a true and lasting romantic love that grows from a mutual relationship.

Puppy love is not bad. It's a normal part of growing up and learning to navigate romantic feelings and relationships. I'll bet that most (if not all) of the people responding to you have experienced it, and as we have had more experiences with relationships and actually "falling in love" with other people, we have learned to tell the difference.

I can definitely point to a couple of long-term friends with whom I was infatuated as a teenager. I still feel a warm, platonic love for those people ... but after having actually fallen in love, I can definitively say I was never "in love" with those people. I certainly don't feel the need to reach out after years (decades, even) to tell them how I used to feel.

If you have not talked to this woman in years and she lives thousands of kilometers away, you have about a 1% chance of anything positive coming from your confession. If you're not familiar with the Dobler/Dahmer Theory, it's pretty simple. A grand romantic gesture will be well received if the recipient already finds the giver to be an acceptable potential romantic partner. If they don't think of the giver in that way, it just comes off as creepy.

You have said that this woman was not romantically interested in you while you were acquainted. So that tells me you have better than a 50% shot of ending up on the "Dahmer" end of the scale.

Channel your energy into something more productive. Maybe get out into your community and find some affinity groups (hiking, coding, discussion, gardening, whatever floats your boat) and find some people you can connect with in the present instead of dwelling on the past.

Good luck!

(Apologies for the link to the random blog, but it's the best source I found for explaining the phenomenon instead of just discussing the show where it originated. I heard about this theory years ago but I only learned today that it came from a sitcom.)