Head injury help needed

So, I took a pretty nasty hit to the head, and honestly, almost immediately I could just feel that something was off. I can't tell if it’s like a literal dent in my skull or just some super intense, rock-hard swelling, but I'm low-key spiraling a little thinking it might be something more serious than just a bump.
Does anyone here actually have experience with this? Like, is this kind of thing normal, and if it is just a swollen lump, how long does it usually take to chill out? More importantly, how am I supposed to know if I've actually messed something up inside?
Thanks in advance for any info you guys can throw my way.

I took a massive hit to the head, and I'm still feeling the aftereffects.
In my opinion, there's just no way to fix a brain injury once it happens.