Just relax. New puppyhood is a little stressful in the beginning. Get him checked out, dewormed and an overall health check. Your puppy might be picking up on your concerns. In no time he will come around if you build on a solid foundation. It sounds like you are off to a good start with the house breaking?
I have found with my girl, that she is a picky eater compared to other dogs I have owned in the past. I also notice she doesn't care for baths, yet she loves to play with the water stream from the hose on a hot day and dive into her kiddie pool! So if it is her idea, she loves water!
My pup was very aloof in the beginning. It worried me a little but it wasn't long before she began to interact with me. Now she won't leave my side! But I worked diligently with training. Short training sessions, clicker in the very beginning, made the learning fun, did games with her, tons of praise etc.. Mine is not spooky but sometimes she will come upon something and her hair will go up, mind you it could be a trash bag or one day a seven up can, lol, and she will let off and bark...a big bark.
Well good luck, I think you will see your puppy will amaze you!
And all dogs can get worms. You can have a sample taken from his stool and find out exactly what to treat him with!