So my daughter actually is seen by a feeding team because she has a gtube and we are trying to transition out of it. I got really worried too but they said even with regular babies when they teethe they usually slow down on eating. They will eat enough to keep them happy but not as much as normal and when they are hungry they will eat. It's very normal. Low grade fever such as this is normal, constipation is normal. All of these sound very normal. Tylenol can help with the pain. I found freezing small drops of puree and giving it to my LO helped a lot. I'm glad you are going to the doctor to get peace of mind bc I get it and I did the same thing!
Just know that your baby will not starve themselves. It's so normal for them to lose their appetite because of the pain. Try some Tylenol and then just continue offering the formula, breastmilk or solids
Try mixing the formula with the breast milk ( more milk than formula) and Tylenol for the fever and if mixing the milk and formula don’t work try mixing the breast milk with some rice cereal