this is a strange thing that I've read happening to others as well. some people do amazing on raw vegan, even long term, and then others seem to start going downhill.
how much vegetables are you having each day, and any algaes? I find these make a difference, if your digestion is poor, do them juiced or smoothies, and you may need lots. I've taken massive amounts of juices, 10 glasses/day sometimes more, and it helps. now will it turn things around for you, I don't know. if you feel you are in a position to try it for a week or two and then reevaluate, that's great. but...don't put your health in danger, and if there's is some cooked food that will stop this downslide, you can think about that as an option.
are you anemic? and do you suspect parasites (worms) at all because these can majorly mess up your body inspite of the best diet, make you sick and weak and steal all your nutrients.
take care and sorry for this time your having. I am raw vegan too, sometimes 100%, sometimes just high raw. if it's more protein you need, high algae are good, spirulina, chlorella. you can also do almond milk, easily digestable. if you do high amounts of veg juice, you'll be getting alot of protein there too, because it takes alot of vegetables to get a few glasses of juice. you may not have to give up the diet, but just make sure to not put yourself at risk as well.