How do I deal with anxiety and insomnia ?

I think I am suffering from anxiety disorder caused by the knowledge of eventual death. This has given rise to sleep issues as going to sleep seems like what would happen after death ("mini deaths" and thoughts of "what if I don't wake up?"). I have insomnia in some sense as a result; I am unable to sleep unless I completely crash. Moreover, I have a lot of stress associated with it, I can't remember things properly and my cognitive abilities have taken a hit.
A little more background - I have never believed in religion and see that there is nothing after we pass away. Furthermore, a few years ago I had a serious illness where I would completely stop breathing for sometime which generally happened in or around my sleep. At this time, I had approached general practitioners in my country not only for that issue but also for my anxiety but they dismissed my concerns and said I was malingering . Last year I approached another doctor and was prescribed diazepam , it didn't help with the underlying issues. I still get chest pains at times but no underlying issue has been diagnosed
How to I deal with my anxiety? I've tried everything so far from journaling, eating right and excersing.
Asked by Introvert

Dear Introvert, 

I am so sorry to hear that you're struggling with the fear of dying. It is not uncommon to meet people who are afraid to go to sleep to never wake up. Were you ever diagnosed with sleep apnea? I have met several clients who have had a similar fear. They would have suffocation dreams. When they did a sleep study, they found that they had severe sleep apnea. I would recommend that you obtain a referral to have a sleep study done. It might provide you a lot of insight.

I would refer you to a medical doctor to have a full check up and obtain a referral to a ear nose and  throat specialist to rule it out. I would also discuss having a sleep study done in a sleep clinic rather than at home because they tend to be more accurate.

When you sleep, if your nasal pathways are obstructed and you experience loss of oxygenation, it will impact your health tremendously. Poor sleep is often associated to high level of cortisol and weight gain. If you experience apneas, your will become anxious as it will prevent you from experiencing sound sleep. You might end up feeling irritable and depressed too as a consequence. 

Do you ever nod off during the day? Do you feel tired ? 

Eating right, exercising will help. You mentioned that you had a severe illness a few years back. Are you still being followed for it? Was this illness a chronic illness? 

It's not unusual for people who have had severe illnesses, to experience trauma associated with dying. Especially at a time where you felt that you might die, and had to reflect upon your mortality. You most likely felt powerless.

Finally, I also recommend talk therapy to support you in processing your anxiety and help you learn coping and self-soothing skills to assist you in self-regulating. I would advise you to have a sleep routine to increase your sleep regularity and establish a sense of safety. Mindfulness is also very helpful in being in the moment and lessening anxious feelings. 

I wish you a good and sound night of restful sleep.