Hello and Welcome to ‘Ask A Doctor’ service. I have reviewed your query and here is my advice. My thoughts and suggestions are as below. Since you have got trauma to the neck in a car accident the causes for sleep apnoea can be related to it as such a severe injury can cause internal edema that takes time to settle and thus gives the problems with breathing, talking and swallowing. Hypothyroidism is less likely due to such an accident, not really heard or read of. This could have been present since long only to be diagnosed incidentally due to the present problem. The pain in neck that you feel that someone is stretching can be due to the following reason: Muscular as your Doctors have said about. The sudden neck trauma can cause internal bleeding and edema that takes a lot of time to settle. MRI of the neck and spine can tell the exact diagnosis. ENT Endoscopy can tell the internal position. Take an anti-inflammatory along with a PPI. Liquid diet. Strict bed rest. Avoid anything that gives sudden jerks to the neck. Hope I have answered your query. Let me know if I can assist you further.