Poor Boots! It definitely sounds like something isn't right. Unfortunately, these are all very vague symptoms that could be caused by almost any kind of illness, so it's not possible to say what's wrong without being able to examine him and run some tests.
Because of this, I would recommend taking him to the vet for an exam as soon as you're able to. He/she can do blood work, x-rays, or other testing if needed to help diagnose the problem and see what kind of treatment is needed.