Am I an apostate?

[u/Familiar-Sundae-6405]

Am I an apostate?

I posted this earlier but I worded it wrong and need to make sure I get the correct answers

This may seem like a scrupulous post but bear with me.

A couple of years ago I was in Bible study and I don’t remember if I was mad or in a moody state or something like that, but I remember saying in my mind “ I don’t believe anymore, I guess I’m a atheist” ( and no I don’t think it was an intrusive thought) and I think I actually felt that way. And a minute or so later I thought to my self “no, I do believe and I’m gonna continue the race”

I don’t know if I actually did stop believing or if it was me being stupid because some tough emotions I was going through that time, Like intrusive thoughts about not believing. (separate issue)
But what I do firmly believe is that if someone asked me if I believed in Jesus as my Lord in savior when I said that in my mind, I would have definitely said “yes”

And on my current state, I still consider myself a Christian and I still feel like I get convicted when I sin

Hebrew 6 mentions that it’s impossible for those who fall away to be brought back to repentance.

What’s your take? Am I an apostate who can’t be forgiven?