Throat problems since 2 months (quitter)

I was a smoker since last 2 years but I've stopped smoking on 19 january when I had some throat irritation which was not getting better. I was prescribed some antibiotics by different gen physicians for almost a month which didn't help me much so i met a pulmonologist who suggested it's normal infection not any severe disease like cancer. After that i still had throat pain so i went to meet an ent specialist who checked my throat using endoscopy and suggested me that i have granular pharyngitis due to LPRD as there were red lines in my larynx area and he assured me there's nothing like cancer. And he prescribed me naksium-d and multivitamin and asked me to avoid spicy food n warm saltywater gargle. But after 15 day I am still having pain in different areas at diffrnt times in my throat area and also developed an ulcer below tongue but doc said the redness and granular pharyngitis is 10-20% yesterday. kindly help what can be the reason? is it normal? can it be withdrawal symptm? hlp pls