I am 5' 7 too. I let my weight go up about 18 pounds before my doctor poured a cold bucket of water over my head. I have lost all that over the past two years and have about 6 pounds to go to get where I want to be @ 140 lbs.
I rejoined my Jazzercise class 2.5 years ago, and that's really how I lost it. Jazzercise incorporates weights, bands, balls and floor exercise in the last 20 minutes of class, which builds muscle which burns fat. I haven't felt this good in years.
Good luck to you and welcome.