Hang in there.
I agree, at 8 weeks, keep your expectations for potty training low.
For a Yorkie puppy at 8 weeks, I wouldn't expect the puppy to hold it more than 2 hours during the day. Since you live in an apartment and you work, I would recommend an xpen with piddle pads.
My boys do both piddle pads and outdoors. They have a piddle pad available at all times, but we try to go out as much as possible, especially for poops.
Whatever you decide, I agree with Taylor that you have to be consistent. You can change methods as they mature, but stick to one at a time and don't change frenetically. 8 weeks is too early for crate training, I think. I'm not as familiar with crate training methods.
The keys do potty training are:
1) limit freedom/roaming room
2) give ample opportunity to potty, including when the pup first wakes, after meals, after playtime or anything that causes excitement, and many times in between
3) praise happily when the pup gets it right
4) don't get angry when the pup gets it wrong
5) clean accident spots with an enzyme cleaner to remove the scent that may attract the pup to return to the spot and consider a place to potty
Here is my blog about how I potty trained:
Potty Training Small Dogs - Dog Life and Style