Chronic infections symptoms and conditions

I have been on Doxy now for about 6 weeks for a couple chronic infections. I have noticed it does make me sick to my stomach when I take it on an empty stomach. Well, about three days ago I started to feel like maybe I was having heartburn but it was a different feeling. I felt like I had food stuck in my esophagus and it hurt right at the end about where the breast bone ends and up in my throat. I felt like it was spasming and the pain would refer to my jaw. I have never had heartburn much and certainly nothing like this. I hurt all day long and the pain was worse when I ate or drank. Of course I was freaking out until I saw on this site that Doxy can cause damage and apparently a lot of pain. I think it was my fault though because I didn't always take it with a full glass of water and I often took it right before I went to bed and sometimes while I was still in bed. No one told me not to lay down after taking it or anything. The only info i got was a little explanation that it can cause an upset stomach, nausea, and vomiting so take it with some food if that occurs. Well, i would definitely recommend taking it with some food an apple or something and not before you go to bed, and drink a lot of water with it!!!
I have a Dr. apt next week but I am going to try not taking it for a few days to see if the pain lessens.

I would be interested to know how many of those who took Singulair needed to take antibiotics more frequently than they did before they took Singulair. I'll see the response then I will tell you why if it turns out that is a predictable side effect.