First off, congratulations on the weight loss, getting control over diabetes, and for turning your life around and taking care of yourself. Good for you. You didn't say where the soreness is, nor how long it lasts during the day, nor what resolves it (e.g., does walking or stretching help make it better?), so I can't address that specifically, but if it's in your legs, and there are no medical conditions causing it (thyroid, anemia, vascular, etc), and no diet issues like lack of electrolytes or dehydration, then perhaps it is just a simple case of overtraining or your weight. If it's overtraining then 5-7 days off will solve the problem. If it's not overtraining, and more from your weight, then it could be that you aren't stretching enough, or maybe you're pushing harder as you get more fit and lose more weight. People tend to move more, and push harder, as they lose weight, whether they do it intentionally or not, simply because it's easier to move. Plus, running on a treadmill is a lot different than walking as far as pounding, and so maybe if you recently started to run, or you've recently increased how much of it you do, then that could explain it. And same thing for hiking. If you recently started, or recently increased it, then that could soreness. And hiking up and down hills is bound to make you sore, particularly walking downhill. Of course, proper footwear for these activities is important.
You ought to measure objectively how much work you are doing. For instance, how far do you go on the treadmill, what speed and elevation, and in what period of time? How much hiking are you doing; how is the terrain (hillier more work and more soreness)? How much walking? If you've been progressively improving on all of these things then it's clear you're doing more work and that might contribute to the soreness.
To help with soreness: massage, stretching, warm bath, light aerobic activity like a walk and then stretching, and ice after the workout all can help. You can also speak with your doctor about taking an anti-inflammatory to help with it (over the counter is usually good enough). But don't take anything unless your doctor approves it.
I hope that helps. If you have more questions feel free to post back.
Take care, Rich