Help! My Kingsnake is not growing!

[VikingzTV]

So I am 15 and I finally convinced my parents to allow me to get a snake back in April of 2015, I got a Mexican Black Kingsnake and named him Thor. I had been feeding him one frozen-thawed pinky (the breeder said he had eaten live 2-3 times up until then) every 6 days for a few months, I fed him twice in one sitting on a few occasions (which he gleefully took).. About 2 months ago, August, I realized he had not grown a bit since I had gotten him.. So I went and bought some fuzzies as well as large pinkys and have been feeding him one every 6 days for about two weeks now, he has shed since then (the day after his first fuzzy) but still seems to have not grown since I bought him back in April.. I just am not sure what's wrong (or if anything is), I will attach two pictures (one from the day I got him and one from a few days ago)