Your symptoms are similar to a disease called Lambert Eaton disease which is caused by calcium channel antibodies found in Mayos Paraneoplastic panel. Look into it. Your on IVIG- so that may skew any blood work you get done. There's numerous antibodies in the panel that are deemed to be the pathogen for many autoimmune conditions ranging from neuromyotonia, Limbic Encephalitis, ataxia, LEMS, autonomic neuropathy, etc, etc.
wish there was a place in the US that provided commercial blood work similar to what CellTrend offers. As this website has pointed out - muscarinic and adrenergic receptor antibodies are emerging in people who suffer from dysautonomia. I've read journals where it's being found in samples of chronic fatigue syndrome/ ME patients. I've read journals where it is found in 70% of Lambert Eaton patients.