Go to a doctor :-)

Yes, you're definitely ill.

Don't try to piece your symptoms together -- get an expert to do it.

Note that it's quite possible for a person to have several things wrong
with them at once, so it may not be possible to find one consistent match
for all your symptoms.

I'm not a doctor, but some subsets of these symptoms are consistent
with a number of disorders, some of which are very serious, and for
which early treatment is very important in getting a good outcome.
If it hasn't gone away by itself these several months, but is instead
getting worse, it's not likely to get better on its own.  Don't wait
until you collapse!

If you don't have a family physician, you may be able to find one
through your local teaching hospital.  A family physician can refer
you to an appropriate specialist if necessary.  In the US it seems
that many people have to figure out which specialist to go to as a
first contact for themselves.  If you're in that position, I'd
recommend an internist.

Nobody can diagnose you here.  Don't screw around -- time may be
critical.  It may turn out that you have something that isn't very
serious, but you won't know until you get a diagnosis from somebody
who can examine you, take a history, and run appropriate tests.

Let us know what happens.