Hullo Lizzie,
I'm a newbie on this forum too (though not posted here on the newbie slot yet...) and though no newbie to a vegetarian diet, over the last few years I've been in a similar boat with the whole dancing between dietary extremes thing myself. And I've found it confudling and not very helpful - for me!
Like you, I've done vegan part-time, raw-food now and then, and fasting, and so on.
If you are having confusions about whats helpful for you and what aint, I'd stop dancing with extremes between raw food/veganism and full-on carnivore days in the same week.
IMO you're probably not giving your body time to balance itself out! The body is a very loyal ally, and a highly adaptive machine, but it sound like you may be sending it mixed messages. All over the globe, people in different cultures have the most particular diets including and excluding all sorts of things, but their bodies know what to expect and are adapted from experience to cope effectively.
I suggest you try to become more moderate in your approach. Why not just do it step by step? Do the *full-on vegetarian* thing for a month or two at least to begin with, exclude all meat substances entirely, then check your bodies rosponses to simple straightforward meat exclusion without any other dietary frills or challenges?
If you feel you need to cut back on meat gradually, fine, just don't compromise yorself by attempting other forms of radical exclusion before you've been comfortable as a full vegetarian, for a reasonable time frame.
My guess is, that you won't notice a thing, so long as your meat-free diet remains fairly stable and predictable. If you do feel 'low', then stock up on a bit of 'Floradix' from the healthfoodshop.
Once you've gotten your system into a healthy rythm without meat - and you feel sound, then start integrating vegan alternatives where they are easy (as I do). It is really easy to slowly experiment with veganism, and then raw or 'life-foods', while also just having the odd day where you're not utterly perfect.
I'd just be careful of throwing your body between dietary extremes in the same week every week.
Maybe think in terms of a month or two excluding 'this or that', one at a time... and then seeing how you go on?
Well, good luck, I hope you find the right way forward for you, Just gently listen to your body, don't get either too paranoid about whats going on in you, or overly perfectionist with your diet too soon.
Green Alice