I have read a theory that Caeser orchestrated his own assassination. The theory was that his epilepsy was growing worse, he had maneuvered himself into a political corner, was running out of money and just could not live up to his fame and nimbus. So, in order to take the "easy" way out and to die with his honor and glory intact, he chose to die an idol.
A fact that supports this theory is that he had been warned but insisted to attend the session of the senate without his bodyguards.
Is there any evidence to support this theory, or has it just been spread to add to Caesar's myth?
I'm sorry to question the questioner, but where did you run across this?
We have several problems with the premises of this theory.
We don't know Caesar had epilepsy. Plutarch reports a rumor (i.e., "as they say") that he suffered epilepsy. He did in some moments have some mysterious illness. There's a particular battle in his African campaign that he for some reason "commanded" (whatever that means) from his tent, rather than the battlefield. Nevertheless, I'm not certain that what Plutarch means by "epilepsy" is what modern medicine would call "epilepsy." Even if he was epileptic, he had planned a multi-year expedition into Parthia he was going to depart for on the very next day after the Ides of March! That does not look like a suicide note.
He wasn't out of money. Caesar was probably the richest man in Rome at the time of his death. Caesar's estate was a point of contention between Antony and Octavian, and ultimately litigated in the Senate. When Octavian won, he paid out 300 sestertii to each Roman citizen out of Caesar's estate, according to Caesar's will, which is a chunk of a year's wage by most counts.
I'm not sure we can take any of the accounts of warning at face value. They make nice stories, but they build the drama of the scene, and it's hard to believe that Calpurnia, for instance, somehow had a prophetic dream that informed her of Caesar's demise. The sources that recount those warnings are decades if not centuries after the fact. A more likely explanation for his refusal to use a bodyguard is that bodyguards were considered the retinue of a tyrant, which he was actively trying not to look like.
So we need to see the actual argument your source makes, because if you represented it accurately, it makes absolutely no sense.