Is this okay to feed my Yorkie?

Your vet is correct. If you only feed your pup human food, he will end up with nutritional deficiencies of vitamins and minerals that dogs need that are not in the human food supply (which will result in unnecessary and expensive future vet bills). Yes, you can achieve an optimal diet adding supplements, but it can be tricky. Amounts have to be precise and if you change ingredients, the supplements need to be adjusted.

I, and many other dog owners, have gone through your pain of trying over a dozen foods to find one the dog likes (when you find it, it's amazing). The tough part is there's no one answer that is right for every dog.

1. If you want to try kibble again, use a meat mallet - or a grinder or processor if the blades are strong enough- to grind the kibbles down smaller or even to a powder. You can add a little water or pure (no onion, garlic, or spices in ingredients) meat based broth to make it more enticing.
2. A middle of the road option is freeze dried. The moisture have been removed during processing. It is either sold dry (like flakes in a bag), which needs to be reconstituted with water- it will have consistency of oatmeal when ready to serve OR refrigerated or frozen freeze dried.
3. The more expensive options include all the fresh refrigerated or frozen, and raw ready to serve pet foods.
4. If you want to explore making your own, check out BalanceIt.com, which is created by veterinarians who are board certified specialists in nutrition & hold graduate degrees in nutrition.