Did I screw up / critique?

Hi jimbo3 - and welcome. Sounds like you started with a gravity of about 1.076 (12 lbs of honey to make 5.5 gallons). Let me ignore for the moment the added puree. Counting bubbles really tells you diddly-squat. You need to measure the change in gravity (density) as the sugar solution (dense liquid) becomes alcohol (less dense). "sweet mead yeast" is a marketing jingle. Yeast ferment sugar to the tolerance the yeast has for alcohol and even bread yeast will handle 10% alcohol by volume without blinking. I have no idea what the tolerance for alcohol is of this Wyeast yeast but I can say that if your starting gravity was as I think, 1.076 you have a potential ABV of about 10% so I would suspect that this will finish brut dry .

But you added 3 lbs of puree and you plan on adding another 3 lbs. If this was commercially made fruit puree it will list the ingredients and that list will include the total sugar content (or it will enable you to calculate that total) There is about 450 g in 1 lb and 1 lb of sugar will raise the gravity of 1 gallon of water by about 40 points . If you know the total number of grams of sugar in the puree and you know the total volume you are diluting this in then you know the total increase in gravity points. Leaving aside whether there is likely enough nutrient load in DAP (there is nitrogen but that is only one element that yeast needs to maintain and repair their cell structure), As long as the potential total ABV is below the tolerance for alcohol of the yeast the yeast should ferment all the sugars. That means, as I say, your mead will be dry BUT once you know that there is no more fermentable sugar remaining AND you know that the tolerance of the yeast has not yet been reached then you can add a fixed and known additional amount of sugar to create a sparkling mead. You do this at bottling time. And that amount of sugar will be about 20 grams per gallon (a scant 1 t of sugar per bottle). BUT you will need to use beer bottles or champagne bottles with wire cages to hold their corks .
So bottom line: yes you probably can make this a sparkling mead. But it will be dry.. and often mead requires some perception of sweetness to bring forward the honey flavors and bring out the flavors from the fruit. So, while you CAN make this sparkling it may not have all the richness in flavor that you might hope.