I would be suspicious that your dachshund has a disc problem in his back or neck. The symptoms he is showing now are classic for that problem. Of course, worse case scenario for intervertebral disc disease is paralysis, but many dogs just have pain on moving and no loss of function. The problem does not usually resolve unless medications are used, such as prednisone or non-steroidal anti-inflammatories. Until then, your dog may be in pain and lethargic.
Here is an article about this condition: http://www.gcvs.com/surgery/interver.htm
and another: http://www.upei.ca/cidd/Diseases/musculoskeletal/intervertebraldiskdisease.htm
You should get him to your vet on monday. In the mean time, you could give him one baby aspirin per 15 lbs (break in half if you need to), and that may help him feel a little better today. Give it with food.
Let me know if you have more questions!