As mammo says before you say for certain its anxiety you need to get a full check up to make sure all is fine, you should get your bloods done as the doc's will be able to rule out a number of illnesses through a simple blood sample and as it is affecting your chest you need to get an ECG of your heart and maybe a chest x-ray. This seems to of been going on a while so dont delay any longer, go get yourself checked over. Not knowing will only make matters worse and cause unneccessary anxiety and add to your troubles.
If after you have all the tests they come back ok, then you should think about therapy or counseling and maybe a medciation if things are really bad.
Because of your health issue I would discuss this with your doctor, rule out your heart before thinking anxiety. If it turns out to be anxiety, speaking with a therapist will help. You've had lots of reasons to be anxious, so anxiety is a possibility, but always rule out other causes first. Take care.
you have been through and lost alot of things this year,so it could all be anxiety,it usually do feel worse when you are laying down,its when you have the most time to pine and think about things more,so you start to tense get all aggitated,and boom the other things like shortness of breath and dizzieness happens,i would suggest you go to your doctors to rule out anything you think could be causing this,but speak to them about anxiety to.good luck