So assuming this is not a hoax, you should get a second opinion medically. You're saying elsewhere you have elevated cortisol, estrogen and prolactin? What about your thyroid function tests? Have they imaged you from head to toe? Is there extreme eating that might account for the weight gain rather than the hormone changes?
The first concern really has to be a hormone secreting tumour. Couvade syndrome should only be considered as an extreme last option when everything else is excluded, as couvade is actually minimal changes in the male not this extreme. The psychological side of couvade would need to be relied on as the main explanation for such extreme weight change.
If your doctors have latched on to this diagnosis without throughly working you up then you need a second opinion. You need to see a good endocrinologist.
The next option to consider well before couvade is could you be being poisoned? Either intentionally or unintentionally are you being given female sex hormones and other hormones? Who prepares your food?
The idea your doctors ascribe this to couvade and wait until you partner gives birth to see what happens seems odd unless they have a very good explanation for all the changes . They would need to have extremely good reason to believe that.
It's because a quid is worth much elss that it used to be, not because a mars bar is worth more (although I'm sure some of it is increased profit margins masked as inflation gouging customers too)