throat cancer? acid reflux? esophagitis?

I am 35 and have abused alcohol and tobacco for over 25 years. smoked 19 chewed 6. I had a scope at an ENT 3 months ago and everything looked normal. i also have acid reflux and take nexium and suppliment with acid reducers and tums.. in the past when i'd dring and chew on the weekend my throat would hurt for few days but would always get better when i quit. i chew nicotine gum in between. i completely quit both a month ago. however my throat has been very sore for over 2 weeks and have pain and presure in the back of my neck. is it possible i have throat cancer that wasn't there 3 months ago? can it develop that fast or could they have missed something? i also went to dentist and had a oral cancer screen. everything was normal except some red spots on back of throat which he said was probably from irritation. i went to my family doctor 4 days ago and he said nothing looked suspicious in my throat and gave me antibiotics. I do not have strep but do have slight infection in throat. as far as i know i have no pain when swallowing. however I have been taking naproxen to ease the pain so not sure. the soonest i can see a gastroenterologist is in three weeks. done know if i should wait that long. could it be throat cancer? acid reflux? esophagitis? none of above? please help i am scared to death!