There is one, and only one, way to fix this---in my experience, at least (which is, unfortunately, considerable in this arena). That way is: dumping it onto another cake.
Forget about the stout for a while. Let it be. Next time you have a free few hours, brew up a relatively neutral (like a pale ale or blonde) low-gravity ale (~1.040-1.045). Pitch dry yeast like US05 or Nottingham, let it ferment out. When it's done, rack off to another vessel. Then, rack the stalled stout onto that new yeast cake. Then, watch the magic happen!
MOSS HOLLOW BREWING CO.
Aristocratic Ales, Lascivious Lagers
•Scottish 80/- •Sweet Stout •Roggenbier
.primary | bright:
98: Moss Hollow Soured '09 72: Oude Kriek 99: B-Weisse 102: Brett'd BDSA 104: Feat of Strength Helles Bock 105: Merkin Brown
.on tap | kegged:
XX: Moss Hollow Springs Sparkling Water 95: Gott Mit Uns German Pils 91b: Brown Willie's Oaked Abbey Ale 103: Merkin Stout
98: Yorkshire Special 100: Maple Porter 89: Cidre Saison 101: Steffiweizen '09 (#3)