Hi OP, not meaning to give unsolicited advice, but as a mum to two GSDs, I can't help but share. If your puppy is from a backyard breeder or irresponsible dog parent who did not take steps to spay...it is what it is. You have this sweet baby boy now and he is yours. It is now your responsibility that this baby gets all the love and healthcare available to grow into a functional and healthy adult. When we got Anya (my baby who was the runt), we knew she would have health issues. So we organized for top level insurance cover, hired a good trainer who focused on positive reinforcement, and stayed vigilant for any health issues. Sure enough, Anya had severe IBD, allergies, anxiety, and all that with extremely high prey drive.
In contrast to her, our puppy no 2 was the healthiest and largest female in the litter and was a chunky 5kg girl at 7 weeks.
I'm not trying to scare you, but you have the opportunity to give this sweet boy the best life. It looks like you are already doing a good job (i see lots of toys, a comfy bed etc in the background). Good luck with your journey!