I would just like to say hang in there , I've been there & know exactly what you are going through , we were first time puppy owners with our dog Amber ,
We nearly rehomed her on many occasion as she was a nightmare , felt we were doing everything wrong, cutting a long story short we didn't give up on her & she is now 4 years old & pretty good you will get through this , I never thought we would but we did . Your puppy looks adorable by the way x