Re: Need a little help here please...well probably more but...we will start with this
Nail problems can be indicative of many underlying problems. Some doctors will start an examination by looking at your hands and nails. I don't what pitting signifies, but I have often had white marks on my nails that coincide with the timing of surgeries or significant illnesses.
Those things being said, I would go back to the doctor for a full report as to what the blood tests ruled out and what your next step might be. Your significant weight loss is remarkable and disconcerting, alone. Make sure he is aware that you have not been trying to lose weight.
Remember that excessive stress can cause health problems, too, so don't let an off-hand remark or layperson's "diagnosis" rattle you too much. Just keep pushing for a medical answer.