Hello there. I'm not sure what you mean by a L7 disc. There is no L7, L refers to Lumbar and the number corresponding to it means the number of the done. There are only 5 Lumbar vertebrae therefore L5 is the last. Only in a few cases it is a anomaly where there is a 6th Lumbar present. But it's very rare. Here is what you should do, Consult a orthopedician and get a MRI of your spine done to find out exactly where the problem is and the extent of the problem. You can take a pain killer for beating acute pain, but it will just improve the symptom but might worsen your actual situation. Many a times, such problems require surgery, that is only when the case is so worse that medications won't be of any help. Therefore you need to consult a orthopedician and spine surgeon and consult with him to make a exact diagnosis and discuss with him appropriate treatment. Regards