What grade or year of university or college are you in, and what courses are you taking?

You don't want to simply sit and try to memorize word-for-word. Try to make metaphors or re-write it in your words, or make analogies, little stories, etc..., so you can encode is semantically and remember it better. For example, in microbiology (2nd year university course), if RNA polymerase was to go along the DNA strand and encounter whatever molecule, I wouldn't memorize the diagram. I think, and still do, that the DNA strand is a train track, and RNA pol is a big train with small wheels and it zoomes across the train track. The exhaust from it falls like little pebbles and so forth. Basically, cartoons. This doesn't work for everything but if you can learn it in a way of a metaphor or something where you know the meaning, then it tends to be stored better. The textbooks tend to be very wordy and make things rather complex, so simplify it for yourself. Don't change the meaning to something else, but make their definitions easier.

Also, when studying, take breaks. Don't try to sit there for 5 hours and study, it won't usually work for all of the content.

I'm not sure about the nerve damage, as it may be due to the surgery. There's a muscle, called the abductor pollicis brevis and flexor pollicis brevis, which originate from the flexor retinaculum. The abductor pollicis brevis is a "U" shaped muscle from the thumb to the pinky, and the flexor pollicis brevis is the same shape and goes to the same areas. Anyways, I'm babbling about this anatomy for a reason. During the surgery, it's possible the flexor retinaculum (band of ligaments or muscles that goes around the base of the joint of the wrist to forearm. It's possible, that this may have been affected and because many muscles in the hand and forearm go here, it could result in some abnormality if affected.

However, do you have any feeling in that weakened area? If you poke it, do you feel anything? If you cannot feel anything, then I'd say it's likely nerve damage but if you can feel just it's weakened, it could be nerve damage or damage to the muscles or flexor retinaculum.