I have a three year old german shepherd cross bitch and she is is driving me mental lately. She has a lways been a very shy and timid dog and she did not bond with anyone else as a puppy but me. As a result, if I leave the room now and she cannot follow she whines and whines and runs around the room getting herself into a state.
When I am with her, she's constantly very tense and hyper, she never wants to just sit down and be calm or if she does decide to lie down and doze for a moment, the slightest noise sets her off and shes running around again.
Is there any way I could calm her down? Any idea's? Would it be cruel to tire her out with very long walks?

Have you gone to any training classes enabling her to mix? i find it works wonders with a timid bitch where we are not the sole being in their lives to focus on.
I have often and still do tire my dogs out for a number of reasons, ie shopping trip, afternoon out etc theres nothing like a settled dog.

I brought her to training classes when she was six months old for a while but I didn't like the methods they used and it was the only one local to me. We do have another dog in the house, a yorkie but they don't really get on very well..

If she were mine, and this change in behaviour was recent, I'd get her checked out by a vet for a medical cause first, before looking to solve it with training..