Ok, definitely a few things to fix. But in order to help you best we'll need some more info.
What size/type enclosure?
How are you heating the enclosure?
**VERY IMPORTANT** Are your heat sources regulated by a thermostat? Not a thermometer, but thermostat?
What are your temps and how are you measuring temps?
Are you handling the snake at all?
Answering those questions will be important to help you further.
But here's a few things that stand out immediately...
A) why are you soaking your snake?? There's no need to soak him. Especially weekly. All this is doing is stressing your snake.
B) pinkies are WWWWAAAAAAAYYYYYY TOO SMALL for a BP. So are fuzzies. They eat hoppers from birth and typically only for their first 3-5 meals before moving up to small adult mice. Your snake may not be eating because he doesn't even recognize a pinkies as food. They are primarily water since they haven't developed at all yet, no nutrition at all.
C) offering food every 3 days is also not helping. You want to wait AT LEAST five days between offering. Since your poor snake has only eaten a handful of pinkies in a year, you really need to get him eating. And offering that often only stresses him more.
D) he's only shed once because he's extremely undernourished. He's got nothing in his body for nutrition so isn't growing. Shedding is pretty directly related to growth in juvenile snakes. No food = no nutrition = no growth = no shed.
Lastly, it sounds like you need to start from scratch learning how to care for your snake. Unfortunately, if you're relying on PetSmart employees to educate you they're usually pretty clueless and sadly under trained.
Here is a link to the basics...
https://ball-pythons.net/forums/show...ius)-Caresheet
Here is a link to a feeding chart...
https://ball-pythons.net/forums/show...ing-Guidelines
Please do your snake a favor and start doing some research that you should have done long before bringing your snake home.