I would ask this over on the fasting connection where there is a fasting doctor.
there is a small percentage of people who lack an enzyme that allows them to convert fatty acids--I do not know the specifics. I would not want to tell you this is just something you should consider EFT for--and yet, it may be that EFT would help you.
Personally, I used to get all sorts of 'crazy' sensations in my blood. This was years ago before liver flushing and balancing my pH, and most importantly, getting whole food minerals. ( I mean from my food, and not isolated supplements) One thing that comes to my inutitve mind though, since you say the sensation is as if the "blood is boiling", is to wonder--and I hope you will not be offended by this: is there something in your life that makes you feel that your blood is boiling? Something you are incensed or enraged about?
A lotof stuff 'come up' when we take away food, that would otherwise be covered up under the *padding*. You know how people will say "that just makes my blood boil". These things we feel and say are often keys to a belief we are holding. (and are big blessings in disguise) The trouble with many of them (beliefs)is that
when we are feeling protective of self, we would actually almost rather die than be 'wrong'; which sets up a scenario where we hold onto some pretty heavy stuff that can make us feel like crap. I mention all this just in case any of it resonates for you. EFT is what a lot of folks on this forum have found to help with some of the discomfort that comes up with water fasting. Some people object to it though, on the grounds that it's not "Christian", (as they view it) or perhaps they feel it is putting something else ahead of God. So, of course whatever your beliefs are will lead you in the direction they dictate.
Try the fasting connection. I think you will get a clear answer that is more science-based, or that will at least put your mind at ease as to whether there is some contraindication to water fasting, for you, at this time.