What the heck is wrong with my hands? D:/

M'kay. So I wake up this morning, and I get in the shower. I look at my hands, and there is this strange, ink-like residue on my palms. I try to scrub it off thinking it was just dirt atau something and it would be gone. I scrub... And scrub... And scrub and scrub and scrub WITH SOAP. It won't come off. "Alright no big deal. It'll go away." Half way through the day, still there. Won't smudge. Won't crack. At one point I try to pick at a little bit of it with my pencil. The SMALLEST bit comes off... along with some skin. >_> That tells me it's totally STUCK to my skin. I ask my science teacher what it might be. He doesn't know and just tells me it's nothing to worry about. "Okay. Nothing to worry about."
Reviewing what I did yesterday before bed, I did NOT come into contact with any ink, markers, mascara, tar, spray paint, printer ink, squid ink(IDK), etc.
I have NO idea where it came from...

Is there any logical explanation for this?

Here are pictures ._.

That bigger brown mark on the right picture... that's a freckle >w>