Belly button healing
Thanks for inquiry and excellent pictures. Sorry for your struggles. You appear to have an involved surgeon and that is the most important thing. It appears your wound has had progress. These things can take time, but since you are concerned about the increased drainage and odor--it is best you see your surgeon.
Belly button necrosis still not healing 2 months post full tummy tuck?
Thank you for your question and series of photographs. It appears that much, if not all, of your belly button has had healing difficulties and will not survive the procedure. I would recommend an in-office debridement of your remaining tissues and institution of local wound care with dressing changes until your body is able to heal from the inside-out. Voice your concerns to your surgeon, they are your best source of information and treatment.
Belly button necrosis
If you still have foul smelling discharge, then you need to have the dead tissue that remains debrided away. It will heal but will likely leave you with an un-natural appearing belly button.