Disobedient puppy

I got a 7 week old puppy at the end of October and he still isn't trained. He barks for attention even though I give him attention. He pees and poops in the house. I take him out frequently and he does go outside sometimes but other times he just plays. He doesn't listen when I say stop and no. I am getting furious lately as I'm 19 weeks pregnant and I figured he would be trained by now. I've had dogs all of my life and this is the most stubborn one yet. He's a mini dachshund. I read up on the breed before getting him so I don't mind the potty training I knew it would be an issue. But he doesn't listen when I tell him stuff. He chews on everything and when I yell no he doesn't care. He runs away with the object. I have to chase him down and take it away and say no chewing and I whip him and call him a bad dog. When he's good and potties outside and listens I give him treats. I am at my wits end because once I have my baby I won't want him being disobedient anymore. He isn't a mean dog, he's sweet and loving but he's just stubborn and doesn't listen. What am I doing wrong?