I've had my first snake for a little over a year now. I know he's healthy because of a recent vet visit, but he doesn't seem too happy. For the past month now he's seemed very anxious and shakey when I'm around. His humidity and enclosure temperatures are fine, he's been eating normally and I haven't moved anything in his enclosure. He's also shedding very slowly and in small pieces instead of all at once. He's been allowing me to handle him, but for the first time today he hissed and struck at me, he's never done either of these things before. I'm really not sure what to do since he is my first, and only snake and I've never experienced this before.