Please help understand what Ray Bradbury meant

In the ‘Ray Bradbury Theater’ series there’s an episode about two dueling authors: an established bestseller writer and his young challenger. The young guy accuses his older colleague that he has written so many books, all of which were excellent. ‘What’s wrong with you?’, he asks in despair.
Here goes the answer of the older writer:
— Genes, chromosomes, I was born a pomegranate. Full of seeds.
And here is the monologue of the young challenger:
— Yes. And that is the final reason why I hate you. I was born a poor beast with no seeds. I have labored 18 hours a day, 7 days a week for 7 years to be, to become, to achieve. And became unachieved. Nothing. My heart was high, but my chemistry pathetically absent. There can’t be no room for me in a Universe inhabited by you.

Please help me with these three questions:
1) What does the expression ‘heart is high’ mean?
2) What does the writer mean by ‘absent chemistry’ here?
3) How do you understand the whole sentence?

Thanks a lot.

Thanks a lot Gillnetter

I am not sure why this thread was closed, but I have re-opened it. I, personally, think that Gillnetter's answer was all we needed, but others may think differently.