You sounded like me there for a minute! At least a short while ago. I am down to maybe one coke and one coffee a week now. Still do eat chocolate. But I was definitely addicted to cola for a while there. I've been drinking an herb tea (cold) called getthetea, which helps me avoid soda and other sugary drinks and detoxifies as well. I also got some new reading glasses a few weeks ago which has really helped my vision!
All that to say, I prayed for you today with empathy and asked the Lord to show you what you can and should do to feel better and see better. I also asked for his mercy today, to lift the pain that is so debilitating and give you relief. I asked him to give you strength and wisdom in kicking the caffeine. You may need to experience another headache, for a few days even, but it is so worth it!