What should I do? Carcinoid symptoms but no answers.

I'm a 41 yr old male and for the last 16 months I have had almost daily flushing (face, ears, chest, upper back/shoulders) episodes along with slight tingling in my extremities. I have had more tests than I could ever imagine. I DO NOT have diarrhea, wheezing, heart palpitations or any other carcinoid syndrome symptoms. Aside from a little weight gain. After a few tests ordered by my GP that didn't provide any answers, I brought up the possibility of carcinoid syndrome and he ordered urine 5HIAA (2.1 mg/l) and chromogranin (61 ng/ml). Both came back within range. I've had MRI's on thoracic, cervical, and brain. I've had abdominal and chest ct's as well as an ultrasound on my liver. Really the only thing that was found was that I have mild fatty liver and 3 small pulmonary nodules on my lungs that have remained stable for the last year. My ferritin is also slightly elevated. I've since seen an endocrinologist who ordered more tests (Cortisol, TSH, T4 Free, Metanephrine Free plasma, IGF-1, Tryptase, another urine 5HIAA) and they all came back normal. I've seen a couple dermatologists who have treated me for Rosacea, but no creams or anything has helped. I'm currently on a clonidine patch to help with the flushing, but I've not seen much improvement. I've even had an autonomic reflex test and a sweat test and neither of them indicated anything abnormal. So, I am left with daily flushing episodes triggered by working out, anxiety, sun/heat, sometimes alcohol and sometimes it happens for no reason at all, just laying in bed at night.
My concern is that I do indeed have carcinoid syndrome, but the tests and scans have not identified anything. I've brought up to the GP how hard it can be to diagnose NET's and that they are often missed on CT scans, but he basically has dismissed me as being overly worried and having anxiety. I really don't know what to do....I just can't accept the fact that at the age of 40 I just started to randomly flush for no reason at all. It has impacted daily life and made social situations much more difficult to deal with.