Having trouble, Help!

"setting the aperture as close to f2.8 as possible"

That certainly allows you to push your shutter speed.

However, on some cameras that aperture will give you a very narrow depth of field. If that gets bad enough, you may have the front of the flower in focus, and the back is out of focus. So, it kind of depends on many factors.

–B.G.–

It's not so bad on my P&S. It might be on a DSLR. Hopefully I can buy one soon and find out for myself.

At f2.8

And as you can see, I need to do a better job of restraining my lens cap!