At 5'10" and 154 lbs you're already well into the healthy range - the natural stopping point tends to be where appetite suppression levels off against what the body actually needs, so if you're eating what you want and loss is slowing, that's the mechanism working rather than a problem. Most people find they settle rather than actively stop; the decision about whether to aim lower or hold is worth having explicitly with your doctor given the A1C context that started this.