Hello guys, this is my looks long but it's really interesting. So I quit smoking and started vaping 4 months ago I took an Evic VT mod from a friend who smokes halo e-liquid (they don't clarify their PG/VG ratios on the normal bottles) it was 12 mg liquid all tobacco flavors and the resistance was something like 0.5 ohm, because I was new to vaping I vaped like I smoked (direct lung hit) the high nicotine burned my throat but nothing serious, I vaped this stuff for like 3 weeks and I didn't have any side effects what so over. Then I bought an Evic VTwo mod and I order sample e liquids from halo (all standard PG/VP ratios) nicotine strengths were 3%, 6% and 12%. I vaped all of them without any problem too but felt like 3 and 6 are low in nicotine so after I finished the sample packs I ordered 12% bottles and 0% with similar tastes in case the 12 was rush for me, then one day I learnt about mouth to lung vaping and when I tried it it was way better for the flavor and vapor production. It was all fine till about 3 weeks ago, whenever I vape I had this weird feeling in my chest like its sore from working out, it will last for some hours and then it will go alone, then the next day I won't feel this in my chest but in my throat like it doesn't feel sore but I feel something like a tiny needles in there, like something is wrong. I did a medical check and all was clear. This will last for a day and then it will disappear, for example now I don't feel it in my chest or throat but I feel it somewhere under my chin. I tried 3% nic level now and it's the same, I mostly have it in the morning and it will decrease through the day. Also it only happens when I vape. - If it's a PG sensitivity or allergy then why I didn't have it long time ago? - If it's from nicotine then why I have it now when I vape 3% and didn't have it when I vaped 12%? - If it's VP sensitivity or allergy then again why I didn't have it long time ago? - I'm not vaping more than usual, I used to vape way a lot before and didn't have any feeling like this. - I'm using same liquid brand. The only thing that I changed is that I'm not doing direct lung hits anymore but instead doing mouth to lung vaping. Any suggestion would be great guys, this is really irritating and annoying and I don't wanna leave vaping and go back to smoking after 4 months. Thanks a lot in advance.