idk what to do

If you want to say something rude please don’t even comment at all.

I need you guys to be open-minded about what I’m going to say because I know this might sound confusing.
So basically, I met this guy on an app and we talked for a couple of months. Eventually, we started talking on Instagram, and everything was going good until we ended things because of some stuff that happened.
I have a fake account, and on it I followed this girl. I don’t know if she’s actually his friend or if he just followed her because he thought she was attractive, but she followed me back.
Around the same time she followed me back, the guy I was talking to deleted his Instagram and basically disappeared from all of his social media accounts.
Then this girl posted something on her story that related to what I was going through, so I replied and mentioned how a guy had deleted his account and now I couldn’t even look back at our old messages.
She immediately responded with, “So I know that person??”
I was confused and said “huh?” She explained that her best friend had also suddenly deleted Instagram without telling her why.
That instantly made me wonder if she was talking about him.
I asked if her best friend was a big social media person or someone who was really active online, and she said no, not at all. That also matched the guy I knew.
So I asked for her best friend’s name just to make sure, and she gave me a completely different name.
The problem is, almost everything she described about her best friend matches the guy I was talking to and what he did. The only thing that doesn’t match is the name.
Now I have this gut feeling that maybe he lied to me about who he actually is, but I genuinely don’t know if I’m overthinking it. Obviously what she said doesn’t prove anything, but the similarities are weird to me.
There’s a lot more context I’m leaving out because this would be insanely long, but this is basically the simplified version.
He also still has one social media account left, and his birthday is on the 30th. I was originally thinking about texting him happy birthday, but now I don’t know if I should because of all of this.
And before anyone says he clearly doesn’t want me and I should leave him alone, that honestly might be true. But our last conversations are part of why I’m so confused.
At one point I told him I wasn’t going to talk to him anymore because I thought he didn’t want me. He responded, “When did I ever say that?”
I said, “You never did.”
And he said, “So then?”
But later, when I actually asked if we could get back together, he told me no.
That’s what doesn’t make sense to me. If he didn’t want me anymore, I don’t understand why he questioned me when I said that he didn’t want me, but then later said no when I asked if we could get back together. Everything was just so sudden, and I never really got a clear explanation for any of it.
Now with this girl saying all of this, I’m even more confused because part of me feels like there’s something I don’t know. I know none of this proves that he lied about who he is, and I could just be connecting things that aren’t connected, but I have such a strong gut feeling about it.
I honestly don’t know what to think anymore. Do you guys think this could just be a coincidence, or does it sound like there’s a chance he lied to me about his identity? And do you think I should still text him happy birthday on the 30th?
Sorry if this was confusing, I’m just really confused myself and trying to make sense of everything.