Svadharma ?

Lord Krishna in the Gita says that it is better to die doing your svadharma than excelling at paradharma. What is this svadharma ? How do I identify it ? So many books and scholars say so many things but it does not make sense to blindly believe them ?
Is svadharma something that gives true joy ? Peace? bliss ? What is it that gives constant bliss, joy and peace. The mind, especially a well-read mind (or even a partially read mind :) jumps up with so many many answers. But these are some areas where the mind is not to be blindly trusted. Or trusted at all. The answer should come from the antaratma, beyond the mind. What is my svadharma ?
Like the disciple who arrives at the answer of "Who am I" by a series of elimination, eliminating a whole lot of who I am not, am I to realize my svadharma that way ?
It is not being a programmer, it is not being a research student. I may fail at these things or achieve marginal success if I work hard at them, but they do not give me lasting joy and peace. Is naren's way of "doing things excellently and 'making' yourself happy" substantialy better ? I'de rather be miserable for a while and get the whole point than sustain the illusion. Like the dwarapala's of Sri Maha Vishnu preferred to be born as his enemies and spend 3 lifetimes apart from him rather than so many more as his friends.
And as a side note, while reading about draupadi and what is really the meaning of Krishna Sakhi I found this excellent link.
http://www.boloji.com/hinduism/panchkanya/pk01.htm
Good stuff man good stuff ...