I understand your concerns about your health. From the information you have given, it appears quire certain that you are having an anxiety disorder called panic disorder. But before we can make this final diagnosis its always advisable to get a ECG done to rule out any cardiac cause for the same. But considering your age, panic disorder is the more likely diagnosis. For it to resolve,you will have to visit a psychiatrist
who can start you on some medication like Paroxetine
and also like to engage you with Cognitive behavioural therapy. Also you can start exercising, have a good and health food and try talking about your problems with someone close. Try relaxation by means of yoga or meditation
which will also help you.
Hope I am able to solve your concerns.