Explain StemVita and how good is it?

As you have learned the hard way, hairs cannot be transplanted as close together as they grow naturally. Think of each hair follicle like a tree with its own roots system (blood supply). When you take that tree from its original place at the back of your head and move it to the front you have to cut a hole big enough to fit in its roots in the new location while also trying not to damage too many of the existing hairs in the new location (note that these will eventually thin and die over time, but we want at least your initial look after transplant to not look too bad.
Which leads me to the best way to improve the look of your hair - rather than focussing on only growing those hairs in between - we should instead be looking to prevent what is causing the problem in the first place.
Going back to our trees analogy if you have a pest which is eating away at the roots, no amount of fertilizer whether it be minoxidil, PRP, stem cell therapy or anything kind of growing agent is going to make it grow unless you first get rid of the pest which is causing the problem.
And how do you get rid of the pest?
First step is always to understand the underlying root cause of the problem. Find a hair doctor who can perform a biochemical report card lab test to identify exactly what is going on for you and then resolve that issue. Then you will be able to regrow your hair.