Thanks Archus. As you suggested I will get my magnesium, vitamin d and iodine test.
I do consider long fast, as some experts suggested, I will slowly increase the duration of fast. When I consider long fast, I will go go Vipasana meditation for 10 days to deepen my spiritual expereince as well. (https://www.dhamma.org/en/about/vipassana).
During 10 days no communication, limited access to phone and email. I will chose a location that has best weather.
I will do so after I two or three 48 hour fasts.
Do you have any other suggestions Archus?
I ordered Epsom Salt, expecting delivery this week. This might help to reduce sluggishness in the muscles.