drysuit sizing

Hello all, I am just transitioning into cold water diving. I was measured for a custom drysuit but the seller told me that the factory said not to bother with a custom size and that a MS would fit me well. I received the suit and am thinking its too big. What do you think? I've attached...

So I'm looking to make the leap into "cold" water diving up here in the Puget Sound. I have been reading user reviews of various drysuits, and have gravitated towards the Whites/Aqualung Fusion drysuits due to their rave reviews, wide availability (of used suits), and promise that they deliver a...