Well we all have to start (or start again) from somewhere, lets take a look.

You have the easing in at the beginning right, but you want to make sure that each and every time you place a foot on the ground that that foot does not move until ready to be picked up for the next stride. There are too little frames for each stride, so the run happens way too fast. Finally the strides themselves could be a little longer and more well defined.

Honestly, best thing I could tell you to do is to get off the chair and run yourself. See how your legs move and how long it takes to make a step, then try to adapt even parts of ti to your runcycle.

Keep at it, and you'll improve!