Mindy, I do not think anyone was trying to be mean.
Sometimes we get too close to our own animals to actually see what is wrong, and everyone, without exception, gets automatically defensive if they are trying to remedy a situation and nothing is happening, then it sounds as if someone is criticising.
I do not know you and I have not seen the mare, but someone who has is giving, or trying to give, you good advice. There quite obviously issomething wrong, everything is quite obviously notjust fine, or you would not be on here asking for help.
Whatever is wrong, it would not appear to be worms (there is still no proven Ivermectin resistance, btw, I just went and did a search, in case something new had come in, so there is no need to keep rotating wormers, Ivermectin every eight weeks as a base is still fine) I would guess, and it is a guess, that lack of protein would be the next thing to look at. Some Vets are not "Mini savvy" and think they do not need feeding. If they are on good grazing this is often true, and my broodmares get no extra feed unless they look to need it.
It sounds to me as if your mare does need extra feed, and 16% would be a good place to start, plus, I would suggest, Beet Pulp.
I would bring her up to eating at least four cups per feeding and see how she goes, judging her by eye.
I am assuming you have had her teeth checked?
Now, keep your cool, people are trying to help, even if you do not want to hear what they are saying!