Seeing your history, I see the copper-zinc question coming up.
But with constipation this is typical hypo T, as you confirm, but also adrinal fatigue from your history. Been there, both!
Know that mg doses of Iodine is needed to combat a hypo T, in my case I needed to get over 50 mg daily before the good things happened, also the detox started then. Kelp did not help me at all, took it for months.
Where are you from, Europe?