Ahhhhhhh... Black is not normal to me that is lack of circulation - did you have a Long surgery? replacement of the removed area? Bruising is normal but when they rebuild the tongue there is an artery put in place for circulation - this is important and if it is compromised you could lose your tongue or at least the new part. I am surprised you are at home the surgery (I had a similar one ) is quite involved I heal well a quickly and I was in for 10 days). Definitely see your dr. ASAP. Just to be on the safe side, are you being treated at a comprehensive cancer center,.. I would be surprised if you are - are they talking follow up treatment ? Sorry for all these questions but when I hear something out of the ordinary I like to clarify. Multiple recurrences in such a short time tells me they are not getting it all despite clear margins. It could very well seed or have seeded to your nodes. Pain and the color are cause for concern, go see your dr. My tongue hurt a bit post op but for the most part I wasn't in severe pain. Hugs