I sliced the fleshy part of my thumb a few years back... Kinda looked similar to yours after the blood stopped bleeding as much and they cleaned it out. I however did not think it was awesome at all at the time. At first they stuck the needles inside the flesh to freeze my thumb because the doctor had to go and "feel around inside to see how bad it is." Even though it was frozen I could still feel him digging around in there. They eventually had to freeze my whole hand from the wrist up with a couple of needles. The nurse was fascinated because she could see my nerves sticking out. Everytime he came near that nerve I would scream or yell and my thumb would just twitch or something even though i had zero control of it... it wasnt even painful because most of my hand was numb it was just a weird sensation you get when there's a doctor stitching up your hand from the inside out. They only gave me a pill of something to ease the pain and relax me but i wish they would have just put me under. I even almost passed out a couple times I was just exhausted and dizzy. It was one of the worst experiences of my life but it could have been way worse the doctors said. Same thing with what happened to you. I somehow missed all the nerves and the bones and any veins or whatever else is in a hand and only sliced the meat. I still dont have complete feeling over that part of my thumb and for a long time it just has this weird "electrical" numb feeling whenever I would touch it. It took weeks of physiotherapy afterwards before I could even start to be able to move my thumb again.

0/10 would recommend.