you need to see a medical professional immediately. If you are having this level of pain there is no point or benefit to ask members of this forum; who are all volunteers who do not work for Apple Computer; or to take results from a web-search as peer reviewed medical evidence or anything else. Conjecture is not conclusion and you could be ignoring a far larger heath issue by assuming it's one thing when in fact it could be something else entirely, or it could be a combination of things, and ignoring that may needlessly exacerbate your issue.
None of us, including Google can determine that with credibility. Make an appointment with a Medical Professional, See a doctor. this is not a medial site, we are not in any position to offer heath advice other then stop using the phone immediately if you think you are at risk from futher discomfort.