I regret getting a puppy and I don't know what to do.

Well, pets are a huge responsibility, especially dogs because they can get hyper. It's sad to hear you regret keeping the dog, but it is understandable as to why you don't want the pet anymore. It's better to admit that you aren't ready for the responsibility and that you want to focus on yourself and your relationship with your boyfriend. Look for a loving family to adopt the pet, someone who will give its 100% love and affection.