What stitch length did you set the machine for? The BSR should speed up or slow down depending on how you move the fabric, but I think you need to specify a stitch length so it knows how big to make the stitches. When I use mine - and granted it's not that often - I also adjust the machine speed slider to low or medium speed.
It would be worth asking another dealer for help - while they may not have sold you your machine, they can sell you feet and other Bernina doodads, with the hope that a happy customer will come back when you're ready to upgrade your machine.
Good luck and happy new year!
Janet