First off, you are speaking of a service dog like you can just pick one up. I think you mean "companion animal" which would be able to accompany her to some places but not all. A service dog is usually trained by a non-profit. I raised seeing eye dogs for a national seeing eye dog foundation.
This dog needs to be taken back. To even start training a companion animals you need a calm natured, intelligent and willing breed. Think lab, golden or german shepherd, australian shepherd, etc. This is not the dog for you.
That is amazing that you did that. I was at the movies once and the person in front of me had a golden retriever puppy who was being trained as a service dog. He couldn't have been more than 4 months old. He had a little bandana stating "Service dog in training". My daughter wanted so badly to pet him and play with him but I told her we couldn't interact with him. I was shocked at how well behaved the dog was. He sat down next to the owner. Took a nap for a while. Woke up and looked around. Never got up to walk away, no barking, nothing. So impressive. He'll make a great dog for someone some day.
I agree with other posters that OP's dog must go back. Picking up a dog from the pound is awesome but it has to be a good fit. It has to get along with family members and other pets. And you have to think about what training you are willing to commit to in order to have the dog you want.
If the dog is a good fit (with the exception of his hyper active behavior and fact that he isn't housebroken), you can pay for a trainer. It's expensive but worth it if you want to keep the dog.