Sciatica and dequervain tendinitis

There very likely could be a connection, but besides general terms only a practitioner whom you see and has the ability to personally inspect and diagnose you will be able to offer real answers. Generally speaking in Chinese Medicine weakness in certain systems like the liver (the Chinese system, not the physical Western organ) and the blood can lead the tendons drier and/or weaker and less responsive to strain leading to inflammation and injury.

With these issues and intense thirst you more than likely have an empty heat condition or what we call Kidney Yin Deficiency. There is little you can do with acupressure to remedy these types of issues, particularly not until you have a very concise diagnosis from a practitioner.

For tendon related issues - GB 34 could be useful as acupressure and for yin related issues KD 6 may help. Again, however, proper diagnosis and full treatment from a practitioner would take you much further.

If yout blood sugar is normal, I suggest examination of your hipophysis;"diabetes" means "being thirsty".There are diabetes mellitus and diabetes insipidus (normal blood sugar level, but still drinking and urinating a lot).TCM could be supportive, in this two possible diagnosis, or elective if no abnormal lab findings.