That's awesome progress. I would strongly recommend trying a lifting program like strong lifts 5x5. You can start from home & get familiar with the movements you will need to learn with this: http://goo.gl/HnViBp (get the 20lb one) After you're comfortable you'll need to go to a gym where you have access to a squat rack and a bench press.

Strength is something everyone should have. The best way to build it is with bodyweight exercises (push up, squat, pull up, etc) and barbell training (see SL)... with this you can look forward to more than just a declining number on the scale.