Everyone has given you great advice, I'd just like to add that I would change up your cardio a bit. I used to be really winded on the treadmill at first too, but the only thing that will fix that is pushing yourself a bit. Your incline is way too high, bring it down to about 1.5% or 2%, anyone would get winded doing 11.5.
Also try this, for your first 2-5 mins walk at speed 2, then for the next 5-10 minutes push that up to 2.5. If you can, do the next 5-10 at 3, and then come down again to 2.5 and then 2 if you need to. The more you push yourself the easier it's going to become, and if you can only do a couple of minutes at a faster speed, that's fine, slow it down again till you catch your breath and then speed it up again. After 1-2 weeks of doing this, I'm positive you'll be able to do around 20 minutes at speed 3 with no problem, I mean it will be a workout, but you won't have to stop. (Then you're just a hop skip and jump away from actually running on the treadmill
Also pay attention to your heart rate, you want it up to where you're working hard, but not so hard that you have to stop. Good luck!
One last thing I do to help push me is, I create a playlist on my ipod specifically for the treadmill. At about the 13-15 minute mark (about 3 or 4 songs in) which is when my mind starts to wander, and I really want to get off, I put a song that always makes me want to dance, since I can't really dance on the treadmill, I find I always start walking a little faster lol, and that pushes me through the next 4 mins. Once I see 19 mins past, I'm like bahhh, only 10 to go, I got this.