Hello guys! So i've bought my first box mod (coolfire 4+ storm edition) yesterday and got 12 mg 50/50 juice with it. At first there was no problem with all, as any other new to vape guy I'm vaping quite a lot , when i say a lot i mean A LOT, let's say ive smoked for the past 10 hours like 6-7 ml of that juice. But last night it kinda gave me a bit headache , thats okay. And today as i said I vaped a lot and now I have something like a stomach ache and feel like my stomach is full although i havent really eaten much today. I am almost certain that its because of the juice but I'd like to know if it is because I'm new to vaping , is it normal in the begining to be like that ? Is it because of the strength of the nicotine? I am a heavy smoker and thought that 12 mg nicotine would be fine for me, I am willing to change it to even 3 mg if that will solve those stomach/headaches? If i kind of like reduce the puffs that much that i can last with 1 tank 4.5 ml a whole day , will I be okay then? What can you advice me guys, it is not something reaally bad right now , but I'm worried a little bit. I've read that as well as stomach aches there is diarrhea but for me is just the stomach aches and that feeling of full.