Anxiety takes many forms but it is always still anxiety. All the bad feelings you feel each day are symptoms of anxiety: we have read about them here before, we will read about them here again. None of these symptoms are unique to you.
Naturally, you will spend copious time and attention stressing, obsessing and distressing over each symptom. But that will not help to free you of them. Only when you successfully address the actual cause of your symptoms can you expect the symptoms to yield.
Some upset in your life has reached anxiety overload, your mind has had enough. So it blows a few fuses, biologically speaking, and your nervous system becomes over sensitised. In this state it exaggerates all our minor worries and fears ten or twenty fold.
You are concerned for your own mortality, you want to live a full life. But your nerves are over sensitive so the natural concern not to die young escalates 20-fold into an idee fixee that your death is impending. This and this alone is what gives you this obsessive thought. When your anxiety disorder is overcome this and all other symptoms and obsessions will resolve as they are only the product of over sensitive nerves.
The tightness in your chest is not a sign of a failing heart, it is muscular tension caused by anxiety: what Claire Weekes described as 'the horse's hoof in the chest' in her book 'Self help for your nerves'.
You hate leaving your house because your nerves detect your anxiety and are unhelpfully trying to protect you from dangers that no longer exist outdoors such as Neanderthals and sabre tooth tigers. You know very well that when you venture out you will face no danger. It is your fear of the fear of going out that keeps you a prisoner in your home.
Best not to let these symptoms of anxiety rule your life much longer, best to face and overcome their common cause: high anxiety. All your symptoms are well known to people here, with persistence and practice you can gain respite and recovery.
All you have to remember are six words described elsewhere: Face, Accept, Float, Let time pass.