I have never experienced any sort of symptoms from taking chlorella, but I may not have been on a high enough dose. Chlorella is especially good at absorbing mercury, and the symptoms you describe sound like they may be related to the mercury detox that's going on. If you lower your dose they may decrease in severity.
I'm a music teacher, and not a doctor. Anything I post is based on my own experience and lay opinion.
Lyme, Babesiosis, Mycoplasma (Asthma), Fibromyalgia (Soft Tissue Injury), Costochondritis,
CFS (Mitochondrial Dysfunction), IBS (Candida), Hashimoto's Thyroiditis, Adrenal Fatigue,
ITP (Low Platelets), TMJ, Plantar Fasciitis, Schamberg Purpura, Tinnitis, Allergies, MCS