You will all come out the other side, but it can go on for a long while! My wcs was really good as a pup, but my lab was about 2 before the puppy behaviour stopped and she matured into a well behaved dog. Unfortunately people are attracted by the cuteness of a puppy and don't realise how hard, exhausting and emotionally draining owning a puppy is, sadly this is why rescues get so many under 12 month old puppies in, because the owners just give up! Cocker spaniels are demanding, as are many other breeds, they are energetic, like human contact, can be noisy and enjoy life! Make sure you have boundaries, and stick to them. They need to learn what is acceptable and what is not, through positive training methods. Reward them when they are good and teach them that NO, means NO. Letting a puppy do just what it likes will only cause problems in the future.
Although it seems really hard work at the moment you will get there, it won't last forever.