"Is it weird to fall this hard for a group this fast?"
No. The thing you're feeling is something a lot of us felt β the sense that you tripped into a doorway you didn't know was there. BTS makes music that's deliberately built to land like that: it's about loving yourself when that feels impossible, about being soft and ambitious at once, about looking back at the kid you were and not flinching. If it grabbed you fast, that's not a red flag. It usually means the music found you exactly when you needed it. Take it slowly. You don't have to learn everything this week. Start with the song that opened the door, then pull on the next thread when you're ready.
It's not weird. It's actually pretty common. You'll meet ARMY who became ARMY in a single afternoon and ARMY who took two years to notice they were already in. Both are real. The only thing I'd say is: don't let anyone β including yourself β pressure you to immediately watch eleven years of variety content. The fandom is wide. You have time.