Approaching things blow-by-blow.
-> fire a change in atmospheric conditions can cause a flame to change behaviour - oxygen deprivation can snuff a fire out, and an increase in oxygen can make a fire grow. I personally own a candle which has insane fire when it's lit - it's the only candle I own like it, and the flame constantly flickers and wriggles around. It's at least three inches high most of the time. I have no idea what causes it, but it's nothing supernatural and it's nothing to do with me. Fire is unpredictable, violent and reactive, so it's natural that it's "violently reactive" to anything, not just to you. I really don't think that this is anything. At all.
-> feeling hot/hating cold This sounds like a fever. If you went to a doctor and s/he told you that there's nothing wrong, then you could've been provided with a dud diagnosis, could've lied [how are we to know?] or could have a rotten doctor. Get a second opinion - and make sure you explain everything relating to your hot/cold issues. This has nothing to do with Otherkinism, so don't kid yourself.
-> blood have you ever noticed that vampires seem to be a literary euphemism for sex? Likewise, have you ever noticed that blood fetishism and "irl" vampirism seem to go hand-in-hand quite a lot? Also, it isn't just you finding that blood is sweet - I think that it's hella sweet, too, and it's probably supposed to taste sweet. If I were you, I wouldn't be weirded out by blood cravings. See a different psychiatrist if you're worried that there's something wrong, bring it up with a doctor [to pull a possibility out of my very unmedical ass, you could be craving blood due to needing more iron - your subconscious could be going "oh, hey"]. Lastly, don't worry about it. If you are a sanguinarian, then you're a vampire and that's groovy. If you're not a sanguinarian, then you have a craving for blood that may or may not be able to be explained, and that's equally as groovy.
You are not special.