I would imagine that you have to go back to basics with training and begin treating her as if she were a puppy again. She sounds like she is entering her teenage phase and this is notoriously hard work. You
Certain aspects I dont think I can help with as Im not that experienced but with regard to house training you need to go back to basics, ignoring her if she goes inside, and treating/praising like mad when she goes outside.
Chewing - anything that she is chewing that is unwanted you should replace with something that you do want her to chaw - toys/rawhide chews etc
Is she a show or working cocker??
Regarding her being hyper - What are you feeding her? I would probably try and feed her something with no additives like JWB or Burns or a BARF diet if you are happy to try that out. Diet can have a huge impact on a dog's behaviour. Is she being exercised regularly - she should ideally be having about 45 mins twice a day.
With regard to her not liking being on her own - you need to build the time up that she spends on her own gradually, have you got a baby gate that you can use to seperate her in another room from yourself? You should start this off with a very small amount of time eg 1 minute - put her in a separate room and leave her - when you go to let her out ignore her and carry on as normal, do not make a fuss of her. You should then be able to build this time up gradually. If she is whining/barking/howling when you are not in the same room only let her out of the room when there is a break in the whining otherwise she will learn that by making noise she gets what she wants.
Have you tried using a DAP diffuser - these emit Dog Appeasing Pheromones which mock the pheromones let off by a bitch when she has had puppies - these help relax and calm them. I have one of these plugged in my house and the difference with my dog was amazing - Hurley doesnt like being apart from me either and will whine constantly if we are upstairs and he is downstairs, the DAP diffuser has definitely helped.
Anyway Im sure someone with more knowledge will come along and be able to offer constructive advice - these are just some of the points of where I would begin..
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