Thank you all for the encourage ment. Now for the question burning at the back of my mind.... How long do I have before my pup gets to the stage where he is old enough that it is too late to teach him new tricks? Sorry, I am trying to rush him because I am afraid of that happening and then having a wild dog.....
I think what you really want to know is how long does it take to create a habit, or to break a bad habit.
You said he's losing weight cause he's not eating in his crate. You also said in previous posts he doesn't want to eat in his crate. I disagree with others about putting his food in there, then. Feed him outside the crate! As I posted before : If feeding him his food isn't working to make him feel comfortable in his crate, I don't see the point of doing it as the purpose of feeding in the crate is loving the food more than hating the crate and thereby getting over being crated."
Not everything that works for one dog will work for the other. Feeding him in his crate right now is TAKING AWAY from his time outside the crate and being with you and it sounds like he has way more time in the crate than is good for him mentally and physically. Wolf pups may love their den because they feel safe, but they ALWAYS venture outside and play around and get exercise. They don't live in there.
Living in an apartment is a hard thing for a dog. I'm willing to bet that your outside time with this pup is minimal at best. You have a pup that hates the crate. So YOU have to ask yourself WHY, why does he hate it? If you're not coming up with a good reason, here's what I think: he's in there WAY too much and not outside enough. ALL dogs need to go outside for good periods of time.
You have a 1/2 GSD, a large breed energetic dog that needs lots of exercise and loves being with his owner. And 1/2 Cocker, a sweet tempered dog that needs companionship and regular exercise as well. Put those 2 together and you have a dog that needs to be with you as much as possible (!) and needs exercise. The GSD is a herding dog, the Cocker a sports dog. So you can see that not giving him exercise just won't work with him. You have to consider his needs. An apartment dog would better have been a dog from the toy group. You do not have a lap dog.
But now that you have him, you have to make concessions that meet his needs. You have to rearrange YOUR schedule to do that.
So ask yourself honestly about the amount of exercise you are giving him outside of the apartment. Sorry, but an apartment just doesn't provide that, you'll have to take him outside and play til he's tired. Chase balls, little walks, playing on the lawn, exposure to different environments. Take him out in the car and go to fun places, parks, kids' jungle gyms, baseball diamonds (close the gates) and let him run on a long 20-30 ft lead.
He's telling you something with his behavior, unintentionally, but still telling you something. Your job is to read that behavior and find out the cause. Dogs are not puppets. We can't get dogs, just put them in a crate for long hours, take them outside to potty and play for 10 minutes a day and be done with it. That doesn't work.
Bottom line - much more time outside the crate with you playing outside and taking him on walks and other places. He needs mental stimulation. He needs physical stimulation. He's a living thing and he needs what all dogs need, the above.
You give him the above, and he'll come soon to look at his crate as the good place, to take his nap not to live in it.