I genuinely believe you are killing off coils fast due to overly sweet juices and chain vaping. Chain vaping (unless in TC mode) can REALLY shorten coil life. The sweet probably doesn't help anything.
If you do get another mod, keep this one in rotation and clean EVERYTHING up to possibly replacing any 0-rings, that burnt taste can really get into crevices and whatnot. Maybe try some less sweet juice.
If you can/if you can afford it, try to get a reasonably decent mod that does temp control it will stop coils from reaching overly heated temperatures, but that means you need an RTA where you can build your own TC material coil (I think the majority of folks these days are using stainless steel).
If you are a sub0hm vaper I think the Crown Uwell coil offers a TC capable coil, I stand ready to be corrected on that though.
If you are a mid range vaper I WANT to say that the joytech CLR coil offers a 0.5 resistance that is TC capable (again, ready to stand to be corrected on that) but here's a thread on the coil and the multiplicity of tanks that take it. Here's a thread on that coil if you are interested:
eGo ONE tank series – CLR coil
I believe Vapresso offers some TC capable coils, too.
If you are a MTL vaper, meaning higher resistance and lower vapor output with a cigarette style draw, I think options are more limited unless you want to rebuild. I want to say that the Innoken Zenith (which is a great tank and the current coils DO last forever, and I mean forever, I had one I was TRYING to kill off for weeks) and it's a nice option because it's larger (4 ml) and maybe the newest coil is TC capable, I haven't checked the specs yet.
It could be vapers tongue, it most certainly could, it could also be that your mind is tricking you to think that tank will taste "Burnt" because it has for a while. I'd say the other possibilities are more likely but I am also not inhabiting your consciousness so I really don't know.
Good luck and a TC capable mod does NOT have to be overly expensive, a DNA mod, or anything else. There are some great lower budget options out there too.
Anna