
I'm not an expert, but I experienced much of what you are going through. My advice would be to find a food (whether wet, dry or a combination of the two) that your dog likes and then stick with it (as long as it is a good quality food, and the dog isn't experiencing any adverse effects, e.g. allergic reactions, diarrhea, etc.). If I changed my fussy dog's food every time she turned up her nose, I'd be on about my 50th brand by now! One day she won't go near it, the next she gobbles it up like caviar. I've learned that she eats when she's hungry, and is perfectly happy with the same food day in and day out. (I feed Royal Canin dry for one meal, and James Wellbeloved wet for the other).
I've read many times that a healthy dog won't starve itself and believe me, this is true. My little dog often went 24 hours without eating as a puppy until the penny finally dropped and she realised she was getting nothing else. She still sometimes sniffs and walks away, so I pick up the bowl and offer it again later. When she gets hungry enough, she clears the bowl.
Hope this helps, and good luck!