Picking up my guinea pig

Question
Hi!  I just adopted a guinea pig from the humane society a few days ago.  He's been through alot, was at the shelter for 3 months, when he got there he had lice and a head tilt.  So he was pretty neglected by his previous owners.  My question is about picking him up to get him out of his cage.  I have to give him medicine twice a day so I have to take him out and then I want to give hime some excercise.  The thing is he HATES being handled, not only that I think he's terrified...is this normal, is he just not used to me?  Is it possible that he's in pain?  When I try and get him out of his cage, I have to take the top of the cage off cause I just can't get a hold of him in the corner otherwise.  At first he was nervous but today he kept on chattering his teeth (I've read this means he's really angry)  Also, when I pet him he makes a purring sound but I've read that this can be both because he's happy or scared depending on the pitch but I can't tell which one it is...I'm just kind of worried about him since he's been through so much...Please could you help me?

Answer
He most likely has bran damage due to the head tilt, I'm guessing he had an inner ear infection. This will make him disorientated for the rest of his life, it sounds like he likes to get petted, but getting out of the cage is very terrifying for him. The only thing you can do is get him used to your hand in the cage, place it on the bottom maybe with a food snack and let him walk up to or on your hand, then he should get used to you picking him up eventually. sometimes an easy way is to get an igloo or bed in the cage, let the pig run into it, then pick up the bed or igloo and remove the pig from it once out of the cage. It sounds like it is going to take some time for your pig to get used to you, but keep up the work.
Brittany