Thanks for using the forum. I am happy to address your questions, and my answer will be based on the information you provided here. Please make sure you recognize that this forum is for educational purposes only, and it does not substitute for a formal office visit with your doctor.
Without the ability to obtain a history from you and examine you, I can not comment on a formal diagnosis or treatment plan for your symptoms. However, I will try to provide you with some information regarding this matter.
Depression can cause unexplained physical symptoms, such as back pain or headaches and also can increase your response to pain. A lot of research has linked depression and pain to the same pathways in the brain and some of the same chemicals control both pain and your mood, so I wouldn't be completely surprised if your depression isn't well controlled, especially you telling me about the fatigue and irritability which is highly associated with depression. Your dosage of 10mg is also a small dose. Speak to your doctor or psychiatrist about whether an increase in your dosage may help. In addition, certain medical conditions can also cause some of these symptoms such as hypothyroidism or vitamin deficiencies. I would highly recommend speaking to your doctor about these conditions if you haven't already been evaluated for them.
If your symptoms progress to a greater discomfort, greater frequency, or frank pain, then you should have your spine evaluated by a physician and an imaging study such as an MRI scan of the spine.
I hope this information was helpful. Best of luck.