Loving someone, what does it even mean?

Throughout these years I think the purest kind of love is the unconditional one. Loving someone without expecting anything in return. It seemed like something that's really difficult but I... tried doing it anyway. I kept loving someone who couldn't even know what I did or react to it. What's more unconditional than that? She didn't even exist anymore but in a way I felt like she still does.

She is still existing as a part o my feeling that I held dear in my heart.

I was happy.

Well, sort of...

But then, now, I think loving someone unconditionally isn't just difficult. It's impossible. I'm not talking about expecting something in return. I'm talking about the very basic condition of love. I can go as far as I can from her and be content just by looking from afar. For me, the meaning of loving someone is the will to protect them. It's the hope to see their smile, the wish to wipe their tears, cool off their anger, or alleviate their pain. The general meaning of unconditional love is to do all those without expecting anything in return. But even that needs a condition to be true.

She needs to exist.

How can you protect something that couldn't be protected anymore?

Truth is, the feelings started to wear me down. I do think loving someone is always for yourself and not for the loved one's sake but this is different. Even if it sounded a lot similar, it's completely different. But despite knowing all this, I still couldn't find the final answer.

Can this still be called love anymore?