Not sure about the burning sensation you are describing. Never experienced that myself. As the last few posts have indicated, use a process of elimination, by making just a PG/VG base. Vape. Then add the nicotine. Vape. Then add the flavor. Vape. Between each step you need to allow the juice to steep. Steeping is the most important part of flavoring. It literally takes days for the flavor molecules to form their flavor bonds. My juice takes a minimum of three days, but I'm usually out a week or so, before I ever vape it. I can't stand the chemical taste, and that comes from a lack of steeping. Many of my juices have steeped for weeks and even months, before I can say whether I like them or not. I tend to use more flavoring, rather than less, the exception being tobacco concentrates. A little goes a long way. My ADV is a cinnamon Danish with 46% flavoring. Everyone is different and I do not have a good sense of taste or smell, so YMMV. Most of my concoctions are around 8% - 20% flavoring, though. Use the process of elimination method.
By the way, 95% of everything I make just sucks. I have to endlessly tweak to get a new flavor that I like. What I have found works best is to buy a flavor I like, figure out the ingredients, then buy the concentrates and tinker until I get it. This can take many days to "perfect." Extreme patience and careful record keeping. Steeping throws these flavor efforts way out time-wise. But if I'm only shooting for one particular flavor, I can eventually match it. When I first started DIY, I tried to make everything, and everything sucked. Now I just target one mixture and stay with it until I get it. Flavoring is both an art and a science, but more of an art than a science imho. I have the base chemicals to make most concentrates, and this is just way too hard for me. I just don't have the talent. But with the concentrates I can get there, eventually. Good luck to you. Be patient. Keep meticulous records for when you "stumble" across a winner, and Vape On!
Btw, I use The Flavor Apprentice (TFA) mostly for concentrates and Wizard Labs for nicotine and bases.