Does this sentence sound correct?

[claudiarsz]

Hi,
I'm writing an application for a reserch position and I wonder if the bold text is grammatically correct. It doesn't sound 100% correct to me, but I can't really tell why it's wrong:

"I want to be able to conduct my own research, and to have the possibility to master a field of my choice where I am good at and where I feel the most comfortable."

Thanks for the help.

[Alan]

--> I want to be able to conduct my own research, and to have the possibility of mastering a field of my choice, something that I am good at and where I feel comfortable."