In the short term, you can take as much vitamin C as your bowels can handle. When you get diarrhoea or a loose bowel movement, cut back on the vitamin C a bit. I've heard of people taking 18,000-20,000mg for a few days.
I think this is excessive & a waste of money. The excess is only excreted by the kidneys anyway. I take 1500 in the morning & 1500mg at night. I've read somewhere that too much vitamin C (long term) is bad for your kidneys. Don't know whether that is true of not. My kidney function tests have been fine in the last couple of years (since I increased my Vit C).
My TCM doctor told me a few lemons or half a glass of lemon juice each day is adequate for vitamin C intake.
Red Capsicums have twice the amount of vitamin C than oranges. Lemons also are high in Vit C.
If you're going to drink orange juice for the vitamin content, you should press the juice yourself & drink it immediately. Within half an hour of pressing the juice, the vitamin content deteriorates rapidly (which suggests that buying "fresh" orange juice in the supermarket & keeping it in your fridge all week is a waste of money. By the way, fresh oranges (despite the acid content) have an alkaline action in the digestive system.
The only seriously acidic foods are asparagus & cooked tomato. Many other fruits & vegetables have acid content, but not too much to worry about in a good varied diet.
Red meat is another very acidic food. Try not to eat red meat late at night.
While there's a lot of good suggestions for the sore throat, I'd be keen to find out what is causing sore throats for such a length of time, so you can get rid of the cause. I've never actually been formally diagnosed with CFS, but my sore throats, low grade fevers & a host of other symtoms suggest the possibility of CFS.
But I do know for sure that I am allergic to mould. I had to leave a flat about 14 years ago due to mould (& sore throats). As soon as I moved into a different flat (for 4 years), my sore throat went away.
I have lived in my current flat about 10 years, but it was only a year or so ago, that I found mould on the side of my old bed & the wall behind the bed end was damp. My new bed is set about 5 inches away from the wall, but I am still suspicious of mould spores lingering. Once the summer comes & I can leave all my windows & balcony doors open all day, it will be interesting to see if my hoarse voice goes away (assuming the recent thyroid tests don't show anything abnormal).
I got fed up going to the Dr in recent years for all these symptoms. I figure if I eat as well as possible, supported by a few good supplements & plenty of fresh air & a little exercise, my immune system should be able to do the rest of the fighting.
Antibiotics are useless.