You are making progress. I like shots that have catchlights in both eyes most of the time. One suggestion is that these look a little bit "under", meaning they could use a bit of brightening in software, and also, the white balance is just a bit too cool for my taste--the light has that sort of UV whiteners in the fabric look of many Made in China light modifiers of the last few years, so I would suggest that the white balance number needs to be pushed upwards a bit with the flash unit you are using. Also: the flash unit(s) have their own color temperature, and some studio flash units have uncoated flash tubes which are "cool" and others have UV-coated flashtubes, which give warmer light. The combination of flash unit and specific modifier can vary the color one gets, and I think these are too cool. ANother 150 to 250 units higher on the white balance would look better I think.
Your shadow side is blending into the black background...a reflector placed close to you would give your shirt just the barest hint of an outline on that far side, and that would really add a lot of "presence" to your body. I think honestly, what is needed is more light on the body; there's a tendency to light the face and head a lot, and especially at close umbrella-to-subject distances, where the light does not spread much, that the lower parts of a human figure are severely under-lighted by a single, smaller umbrella.
Of course, it depends on what the desired lighting effect is, but if you want the clothes to form a substantial part of the overall picture, I know from experience that with the enclosed softbox type umbrellas at close range, they do not light the body enough if the light is good on the face.