Sweet stout - Stalled or user error?

[Sidman]

Hello all,
Could really use your help. I wanted to try the 2016 Homebrew con winning Girl Scout Sweet stout for relatives this holiday. I followed the recipe and my FG has now settled at approx 1.026. The recipe calls for 1.018 so I thought maybe it's stalled. I checked back at Beersmith and it has an estimated final gravity of 1.028 so now I am confused. Did my yeasties stall out or is there something I am missing here? I had vigorous fermentation for 3 or 4 days. I did make a substitution for the yeast. I did not have time to make a starter so instead of Wyeast 1968 my LHBS guy recommended Nottingham so I pitched 2 packets after proofing them. This is a 10.5 gallon batch. OG was 1.071. I added the 2 lb lactose at boil. This is day 7 and it has been fermenting around 65 degrees. I bumped it up to 68 and gently swirled to see if I could get it to finish up.

So now that I am here, what should I do. Pitch additional yeast or different kind of yeast or am I pretty much stuck here?

 

[ESBrewer]

Can you describe your mash conditions. It seems that these stouts with unfermentable lactose and roasted malts and grains may end up high unless the mash conditions are efficient. I think you are already inside the acceptable range for sweet stouts and could condition and package and see if you like it. If you really need to ferment more you could maybe add some amylase.