It does not sound like yeast infection because after using antifungals , it is very difficult for yeast infection to persist. A very common cause for bad breath and chapped lips is deficiency of zinc and vit B3.Try taking some multivitamin-multimineral supplements for some days and see if the symptoms persist.
If the symptoms persist then other possibilities have to be probed. These include poor oral hygiene, fungal infections on the tongue or in the mouth area, endocrine disorders like diabetes, hypothyroidism and cushing’s disease, anxiety, hepatic and renal causes and neurologic causes. I sincerely advise you to consult a physician/neurologist and get yourself evaluated for these. The cracking at the end of the lips can be due to angular cheilitis for which I again suggest you to consult an ENT specialist.
I hope it helps. Take care and please do keep us posted on how you are doing.
See i was told it could be from a Vit B deficiency and i have been taking vit b pills as well as muti vit pill and i still have it, I truely believe it is some kind of fungal infection i have done alot of research over the past year and i came across an all natural way to help fight a fungal infect and it was eating yogert so i have been trying that for about 2 weeks now and it has helped alittle but once again the problem still remains