I am new here also. I have been taking Vitamin C for years at about 2-5 grams a day. I had not been sick for over 6 years. Last year I was getting shingles (at the time I didn't know what it was). I woke up like normal to start my day, by 10am I realized I was weak and possibly getting sick. I took my normal dose of 3 grams AA V/C. By 1 pm I had a fever and was very tired. I went to bed and continued to have a fever for 6 hours but during that time I took 32 more grams of V/C (I would take it every hour). Around 7 pm no more fever, by 9 pm feeling almost normal. Woke up the next morning and felt great but had a 4 circular areas of itchy bumps on my left thigh. One was more bumpy and it did itch for about a week. Also that leg was sensitive at the top part to the touch for a few hours. I then looked up the pics of shingles and I knew for sure that is what it was. I had been around 2 family/friends that had them bad for the last few weeks. I didn't take any extra C after that because I had no other issues. The only thing was the itchy spot for about a week. If I had taken more it probably would have gone away too but I didn't even think about it by that point because I felt totally normal.
I would just go to bowel tolerance with Vitamin C and do so until you have no more symptoms. That is totally my opinion but I am not giving medical advice
since I am not a doctor:)