To the OP, I've had 5 dogs before and this is my first GSD (13 months, male) I've had him since he was a tiny 7 1/2 week pup.
Trust me, I understand your worry and you being overwhelmed. GSDs are A LOT of work. But I believe almost everyone here in the forum will agree with me when I say that they are WORTH IT.
It is normal to feel overwhelmed. You havr to juggle her needs with your timetable and probably plan out your week in advance every week. There was a time when I felt like my dog was too much, but I never regret it.
He went through a period of pooping 5-6 times a day for 3 months. He had diarrhea twice. I woke up at 6am, he had bad diarrhea in the crate. I was late for something. But I had to clean everything out, not to mention now he smelt like pee and poo. Had to bathe him, had to groom him. When you're late and stuff and your dog is ill, it's the worst. He once nipped at someone, caused me trouble. He peed at Petsmart, cool. Brought him on a short getaway, he threw up all over the cabin floor, which was carpet. Yes, he had 2 accidents IN my room when he had diarrhea, my room is CARPET, I had to bring him out at 3am, clean out my carpet, clean him out, that took me until 5am.
He doesn't want to eat, had to change the food formula. He lunges at people and dogs, had to get training in order. His sheds all over my car and house, I had to buy one expensive vacuum and another vacuum for my car. He cried all week all night when I brought him home, drew concerns from my neighbour. I asked my other neighbour who has a big mutt when they are ever gonna calm down, she says she thought it was gonna be when he was 2 years old, but didn't happen until he was 4.
I don't care. He 'saved' my life twice already. Once when I was drunk, and once when I pretended to be drowning. He plays hide and seek with me. His smile is always there when I wake up. He's good with kids. He's always right there next to me wherever I am. He's the best dog I ever had.
You sound like a caring owner. Don't worry, you're not the only one who's had puppy blues. But trust us, they're worth it. Don't beat yourself up.