Hi, I'm new here

I'd like to ask you for help. I have to take a ampoule (for drug) photo. I need it to make a contour for a box. I put it on a white glass with a light from the botton (some kind of table) and put a back light with big white paper. From left, right and top I put a black paper to accent contour. The phtos is quite well, but I've two problems:

In zoom, the walls aren't sharp enought (it's caused by dimension of ampoule walls), but I'm wonder, if you can help me ?

Ampoule contain some water, and I'd like to accent it by some reflection, but not ordinary light (maybe diffused ?), but If I placed some light it change contour.

Help me please, I'm a beginner