Again, if the exercise you're doing is exhausting you, then cut back on the amount or the speed you walk on the treadmill. Ideally, you should be doing 1/2 hour at a time on the treadmill---preferably with changes in elevation. If doing a 1/2 hour is wearing you out, slow your speed down to the point where you can do the time without feeling worn out. Then gradually work up to a faster speed---a little at a time.
Also, consider cutting back on the chicken and meat that you eat. I've had success losing weight by only having chicken/fish/meat twice a week, and on the days that I do have it, I only have one serving size. In addition, I rarely eat red meat on those days, instead I have fish or white-meat chicken.
Another thing to consider---you've tried many diets/herbal supplements---Just how long do you try a diet or a supplement before you give up? Sometimes you need to be patient and give something new time to work. Some say give it at least three months.
There is a CZ user, "propaul", who has put his type 2 diabetes in remission. He has a blog on CZ where he discusses how he changed his diet and made sure he got regular exercise. I suggest you take a look at it. Personally, I found it to be very helpful.