What Causes Recurring Sore Throat?

Hello! I am 27 Years old. I am a smoker and have been struggling with pain in my throat on and off for about two years now. Sometimes the medication helps, but the sore throat returns within a few weeks and sometimes the medication does not help. I do have trouble with sinusitis and i have gone for a sinus operation. I always have swollen glands in neck. My throat does not burn, just pain in my throat and down my neck. It does feel like i have two little balls stuck in my throat. i also have ear ache. I went to go see an ENT last week, he barely looked at my throat and said my tonsils have to be removed. he gave me antibiotics to use for seven days and i m am scheduled for my tonsillectomy in 6 days from now. He also mentioned a loose gland. I have 2 days left on my antibiotics and my throat is still sore, my glands and ears are also still sore. Do i have reason to worry? is there a possibility of me having throat cancer? should i go for the tonsillectomy and what can happen if i do go for the operation and i do have throat cancer?