Gymming Log!

Take it slowly, ure doing just fine. I used to do 5.0 when I started, for half an hour. Gradually bumped it up, over the span of a few months, and now I start at 7.0mph, and then increase .2mph every 5 minutes and go upto 8mph by the time I'm done. I keep a 2.0 incline as that makes it tougher and targets my thighs for resistance training. Just be patient and stick to the speed you are comfortable with and gradually crank it up.