What is wrong with me?

Hello.
I think I have a problem. I am unable of understanding my own feelings at the moment and so far I’ve been blaming it on me being introvert but what if that’s just an excuse?
Let me make it have sense.
I have this very close friend I’ve met online. We have been friends for three years. I love him I truly do. He is understanding of me but I notice that lately I just don’t want to talk.

I go to college so that already drains me. Texting him now feels like a chore. It’s 10pm and I haven’t responded to him all day. I’ve explained to him that I get tired that’s why I talk to him on weekend so we settled with me at least saying something even small once a day.

It’s fine and understandable but I … dont want to ?
I care for him, he’s a dear friend but honestly I could go days without talking to him and be just fine.
What is wrong with me? Do I lose interest quickly? That sounds wrong but I genuinely don’t know what to make out of it.
I’m happy alone and I know ill be sad to lose him but I just don’t want to talk.
If he was my friend in real life it would have been easier. We could meet up and hang out just to have some time together but now that the years have passed, we know everything about each other , there’s nothing new to talk about so it makes it even harder?
It’s like forced convo (from my side) so to make my presence known and let him know I’m still here.

Sometimes I wish my friend had some other friends where he lives so maybe he gets to interact with people there and I could have some more alone time. Sounds so mean and once again I love him. Truly I do but why do I feel this way.