First off, awesome job at working to improve, and I'm glad you're seeing results and feeling more satisfied in game. Sean has such a great educational program that I'm sure he was a big help for you.
However, there is one caveat about comparing WoL or HotS beta leagues to the HotS final release. Basically, bronze is much smaller, so many previous bronze players will be in silver. Though since you're top silver, that's still definitely an improvement. More info here: http://us.battle.net/sc2/en/blog/9067510/Heart_of_the_Swarm_League_Percentages-3_11_2013