Kind of too late to help you from your batch you made in January, but lagers need more yeast that ales. Depending on how old the dry yeast is (dates are on them) and what your gravity is, you most likely need at least 2 packs of dry yeast. Use a yeast calculator like MrMalty.com next time.
Member of the Metro South Homebrew League (Mash-Holes) - Weymouth, MA
Primary - Dortmunder Export
Secondary - Empty
Kegged - Janet's Brown Ale
Bottled - California Common (2nd place, 2014 OSHC).