OK I want to bring out the tension of a character put into the spot of having to make the winning shot of a high school basketball game. I want to have his emotions and worries as realistic as possible, but my one problem is I have never been remotely close to this situation. I was hoping someone here would have some experience in this and could maybe describe their feelings. I know this could fit into plot development, but I felt my issue was more about the characters feelings and not the moment itself, seeing as I know he's going to make the shot and win.
As they say, write what you know. However, that doesn't mean you need to have been an FBI agent in order to write about FBI agents. What you need to do is think about a time when you've been under pressure to succeed in something. Has a manager at your work asked you to get something done, and done well, and you've sweated over it's quality and being able to get it done on time? Have you ever played any sport and been in the situation where the outcome of the game rests on your decision? It is not essential for you to have done / experienced everything the character is going to. You need to draw from your own life experience and manipulate it in order to apply it to what is happening to the character.
I definitely agree with this. To capture the feelings of the character at that moment, you'll have to dig deep into your own experiences in similar situations. Draw from your own past and use it to understand how the character would feel in that sort of situation.