Things to note about your image:
- The lighting is coming from above and ever so slightly in front of the subject, I'd bet if you drew a line from his mouth directly up, you'd hit the light.
- Appears to be a single light source. Shadows don't look filled in enough to me to indicate that a fill flash or reflector was used
- Shadows are defined but still have fuzzy edges, indicating a small light source was used but not necessarily a point source. Perhaps a small soft-box was used
- The light appears to just almost overexpose the rim of the head and falls off by the knees (if we assume the falloff to be in camera and not in post). I'd fathom the light source is ~3 or 4 feet above the subject.
I would suggest setting up you shot similarly to this one. If your light-stand isn't tall enough, then get creative in attaching the light to the ceiling. The light should be pointing straight down and positioned just in front of you.
You don't mention what camera and lens you have so I'm assuming a newish DSLR and a kit lens (18-55mm). Set your camera to Manual mode, select f/5.6 for aperture (lenses sharpen up quite a bit a couple of stops down from max). You'll need to play with the ISO and shutter speed to see what works...
30W is, unfortunately, not that bright. The sales page for your lights shows them lighting a sock from a foot or so away. That is what these lights are designed to do: light something small and fairly close...small objects, headshot portraits, etc.
Place an object about where your shoulders would be in the frame and take a meter reading through the camera and dial in the shutter speed, having set ISO to 3200, and see what it is. If a speed of 1/500, for example, is good - than we know that we can reduce your ISO. The shutter speed should be in the 1/15 to 1/60 range or faster using the lowest ISO you can get. Note that, in this range, you'll want to use the Mirror Lock Up functionality of your camera.
Because of the low power of the lights, you may have to start making tradeoffs like using a more open aperture at the expense of sharpness. Won't know until you meter!
I'd remove the light-box for this shot and see how it turns out. If your shadows are more defined than your goal, then you need to soften the light (use the soft box). The caveat here is that your soft box may make the lighting too soft...this would indicate that you need a smaller box or to explore some homemade light-softening solutions.
Also due to the low power of the light, it may be impossible to light your head, shoulders, torso, and legs appropriately in a single exposure. If worse comes to worse, you can always lower the light down and take separate exposures for your head, torso, legs, and blend them together in post. It'd be nice to do it all in one shot, of course, but if you lack the gear, make up for it in post ;-).
Should I also somehow isolate myself since I have white walls around so light wouldn't reflect?
Yes. Your studio space should be dark enough to where the only light the camera records is the light you want it to record from the direction that you want it to come from. Most studios use dark/black painted walls, ceiling, and floor precisely for the reason you describe: white wall reflect light. You can get around this by using a very large and open space or boxing yourself in with dark fabric (think of a human sized light-box).