Jackson went through a phase like this around 1 year old. Never did any biting or anything like that, but god he drove me NUTS. He suddenly wouldn't sleep, and he had always been such a good sleeper. He was constantly into something, out of boredom, even though I was giving him plenty of exercise. Anyone who knows of Jackson and I knows that he is a very active boy. But yeah even though he can still drive me up the wall on occasion, he developed a very nice off switch.
I also find that sometimes the more you give them, the more they expect. There have been days where we spent 7 miles hiking, walked through the pet store, went to a dog park, and he still comes home and whines at his toy box. That's the point when I just say 'GO LAY DOWN!' lol... but then there are times when it's been raining for 5 days straight and he's pretty content to just go lay down.
Check out Click to Calm.
Click to Calm | Karen Pryor Clicker Training
Also, always reward for her being calm. Once she's laying down nicely, pet her, tell her she's being good. Sometimes a dog must be taught an off switch.
I'm not against medicating at all, but I think in your case, you just have a teenage terrier on your hands. It's just going to take a little time and patience and training.
It doesn't sound like it's anxiety, or that there's anything 'wrong' with your dog. She just needs to mature and be taught to be calm. Otherwise, have you tried interactive toys? Trick training? Make her brain work, she sounds like she would be fantastic in agility, she's got the energy. Honestly, mental workouts tire Jackson out more than any walk (walks don't do anything for him, except make him 'content'), a good RUN or swim is the only thing I've found that truly tires him out.
Check out Kyjen toys. Whenever he is annoying me, I either give him his Kong Wobbler or an interactive toy so he can play and try to work things out on his own.