Kate I'm truly sorry, but you must remember how concerned a lot of us were when you said you'd got this puppy.
Nothing wrong with having another dog at your age, but a small/medium, older, rescue dog would have been perfect.
Everyone who gets a dog should think long and hard about what type of dog would suit them, and fit with their life and lifestyle.
You shouldn't really have taken on a puppy, and a Springer spaniel, of all things! They can be quite manic - as you've discovered - and no matter what you say, at your age you cannot possibly give him the amount of training and exercise he needs, and should have been getting from the day you took him in.
A puppy is exactly like having a new baby in the house, and I'm sure you wouldn't have dreamed you could manage a baby.
Yes all of this is harsh, but I'm concerned for both you and the dog. Apart from anything else, if he's pulling you so hard, and is so uncontrolled in the house, he can so easily cause you a serious injury.
I honestly think you should very seriously consider whether someone else would be a much better home for Oscar, before he gets any older and untrainable (((x)))
As for that collar you've ordered - makes my blood boil

No dog needs one of those, and if they do then they shouldn't be in a normal home.
Both Jo and I have posted about fantastic leads, all you needed to do was ask, or even better still take the dog to a pet shop and ask them. They would be more than happy to advise you, and for you to try out various kinds in the shop.
If you really can't manage him enough to do that, then I'm afraid you have your answer as to the dog's future.