I really wouldn't consider you a slow responder here!
You're lifting and clearly reshaping your body, swapping fat for lean tissue. Muscle packs more mass into the same space than fat does, which explains why your clothes fit differently and you've sized down even without much scale movement. That's genuinely encouraging.
The number on a scale, or even BMI, misses a lot of what's really happening, particularly for someone strength training. Taking monthly measurements around your waist, hips, chest, and arms tends to give a far more motivating and honest picture of your actual progress.
You've stayed consistent with better eating, more movement, and sticking with treatment even through a slow dose increase. That's clearly paying off. Keep at it exactly like this!