Sharp pain in left index finger. Invisible splinter?

After returning home yesterday, I carried my bag up to my room and when i was grabbing something, I noticed a sharp pain in my index finger, almost splinter like. It only bothers me when I use it to grab rougher objects. It doesn't hurt when I press my index finger but if I use a nail cutter to press onto a specific point, it triggers the pain.

I'm not sure how it came about, but my bag was very heavy when I was lifting it. I didn't notice it in my day before.

As shown in the given photo, there seems to be a large indent. I'm not sure if that's a cut or some sort of splinter, as i cannot see any splinters. There's some exfoliated skin from me trying to remove a suspected splinter however.

I'm hoping that it might just be some cut that will heal in a day or two, but I would like ghee help!

Thanks.

https://imgur.com/a/mGY0x2m