OP,

A few things.

1. The bike is NOT to small for you. It looks like the correct size.

2. You fork is CARBON not alloy.

3. With a CARBON fork the manufacturers state that you can't have more than 30~40mm of spacers below the stem or else you risk damage the steerer (fork). This means that the assembly factory cut the fork NOT the shop.

4. As a newb, the last thing you should be doing is pulling your bike apart. Do you know (really know) how to properly re assemble it? Do you have a torque wrench?

Put your bike back together, get the shop to check it and go for a ride. If, in a few weeks it still feels off have the stem swapped for a higher rise stem as other have suggested.