For whatever it worth, your symptoms remind me very much of an anxiety disorder. Please realize that it is impossible to tell you what this feeling is for sure, but I'll give you a little info on anxiety and you can tell me if this sounds like you:

Alright, so you mentioned you are a hypochondriac - it obvious that you have taken time to look up symptoms and you have found a potentially life-threatening disorder, this is normal if you have certain anxiety disorders. By being able to place a name on the issue, you can have something to worry about. The process of physical symptoms due to psychological problems is called somatization. Often, people will displace, repress or suppress anxieties - which suface somewhere else. Sometimes the person knows where the anxiety originates and sometimes the underlying cause is completely subconscious.

Again, I'm just throwing some ideas out for you to consider, but the suppose the "full-feeling" is simply nervousness (anxiety). Of couse, someone who is going through this process will continually try to find the cause of the problem the physical symptoms, and because of this, you become hypersensitive to your body and amplify any pains aches or discomforts you may feel. By focusing on these health issues, one can sucessfully distract himself from any other stress-causing issues.

Perhaps this is not what you are experiencing at all, but some common symptoms of this type of anxiety would be insomnia, inability to concentrate on daily activities, preoccupation with health concerns, history of anxiety over serious health concerns (i.e. cancer, AIDS, brain tumor, ect), alcohol or drug abuse (sometimes to induce sleep), complete disappearence of symptoms once tests or diagnosis proves negative, inability to catch breath (especially at night) and depression.

The reason most symptoms occur with more intensity at night is that one becomes hyper-aware and there is little outside environmental activity to provide distraction.

Sometimes this anxiety can turn into panic disorder. Panic attacks usually cause one to believe he is dying and are accompanied by extreme anxiety, fear and a feeling of being trapped.

So, some of the reasons why I think this might be useful information is because of your age (most anxiety disorders and depression begin during the mid-20's), also the types of discomforts you are experiencing, the fact that you have a history of irrational fears and persistant belief in a health concern even after seeking medical attention.

Again, I want to stress that there could be other problems, so take this info for what its worth, but anxiety disorders respond to a variety of treatments. Most involve cognitive or behavioral therapy, psychoanaylisis, or medication. Anti-depressants (SSRI) have proven effective as well as some non-SSRI anti-depressants such as wellbutrin. Also, in case of moderate to severe anxiety, benzodiazapines (such as Xanax or Clondopin) can help in the short-term.

So, if this is interfering with your life - which it obviously is, regardless of whether it is truely physical or psychological, one should seek assistance because otherwise systoms could get worse.

Hope this provides some help or comfort. Hope you feel better and please feel free to ask any questions.

-Pete