If you're only sticking with the same workout program for a month, that might be where your issue is. When you're first starting out, if you're lifting and you're eating well and you're doing it consistently, you're going to make progress - especially if you had thirty pounds to lose (great job, by the way!) to begin with. Only giving your body a month to adjust to a program, however, isn't enough time. It typically takes about twelve weeks or so for the body to adjust to a program enough to actually make real progress. If you change things up too often or not often enough, you aren't giving yourself the chance to make as much progress on that routine as you could.
Also, what exactly are you doing lifting-wise? Specific lifts, reps, weights, etc? Adding more days or increasing volume doesn't necessarily make a workout more effective on its own, so it would be helpful to get more details.
Don't get discouraged - it's always easier to lose the weight when you start, but everyone always has a sticking point where their progress always slows or even stops altogether. It's one hundred percent normal. You already have a lot to be proud of, and as long as you keep working at it you will end up making more progress.