I am losing my mind this week, but I'll try to condense my story

it seems that my little girl who is usually a good eater had a few things going on this month. First she lost a baby tooth, then went into heat, and then had a really bad lip breakout (very itchy and painful for her), since then she has snubed all her food.....I mean everything except "treats"
I have cooked all of her favorites, boiled chicken & rice etc. and even tried putting cottage cheese or cream cheese on top to excite her, but still nothing. We leave her kibble down but it looks untouched.
I read another post that suggested a Tbsp. of EVO mixed with the food and went out this morning to get a can. Just now I tried to give it to her and she literally smelled it and ran away, then I opened another holistic food that she also turned down, then I cooked her an egg, this time she sniffed it and tried to bury it by flipping the dish, then went back to other food I just put down and tried burying that too. In my frustration I gave her a few 'treats' and she ate those with some hesitation and yet other times she will scarf down the 'treats'. It seems like she is hungry but she won't eat! I give her treats becuase I want to see her eat something.....anything! but I'm also wondering if she is playing me? (she loves her 'treats') I know their have been other posts on this subject but my girl has NO health issues and has always been a good eater, although as she gets older she gets more and more picky. My other yorkie is the opposite, it seems thee older he gets the less fussy he is.
also she is pooping normal (although last night it was a little softer than usual).
does anyone have any suggestions? I would be so grateful! I'm going crazy over this!