Your leg looks pretty good but (always a but there huh? :) ) as others noted you need to sink into your heel. The heel problem is coming from your upper body and as also indicated, you are jumping ahead and are over the pommel of the saddle which is very common when learning to jump.
You need to just close your hip angle and "push" the horse away with your hands..this will help keep you over the center of the saddle. It will also help with your release, which from this angle, looks like you just dropped your hands onto the withers?
I am normally one to say shorten your irons but in this case they may actually be a little TOO short :). For normal riding (flat work) you want to take your foot out of the iron, drop your leg and let your foot relax. The iron should hit right at the ankle bone. For jumping, shorten that length by one hole and once you get to the 3 foot mark, shorten by two :)
Your back is flat and eyes are up, which is critical :)..always remember that your body tends to follow your eyes.
You are doing very well for only 7 months :)