DC: Don't panic too much.. the body has several plateaus, where it feels comfortable at (and as you yourself say, you've converted a ton of fat into leaner muscle).
If you want to see the ridiculous ways that others try to force the body through the plateau barrier...
At Nightfall, Ted Forrest Wants Two Things: Matusow & H20 – #1113 – 2010 WSOP #94 | FULL TILT POKER BLOG