Making a matrix in a for loop

I am currently working with mathematica and I got stuck on some technicalities.

Rvec[R_] := UnitVector[Length[R], RandomInteger[{1, Length[R]}]]
Fvec[R_] := R - Rvec[R] + Rvec[R]
vec[R_] := Module[{S = Fvec[R]}, If[Count[S, -1] > 0, R, S]]
Loop[R_, n_] := For[i = 1; L = R, i < n + 1, i++, L = vec[L]; Print[L]]

The idea is that I now have a loop going that will randomly subtract one number from one entry in a set and add it to another in the next iteration, but with the catch that no entry can drop below zero. The output I then get is a set of outcomes put beneath each other.

Having done that I would like to know how I could put the entire output in the form of one matrix:

http://ift.tt/2ffaTfR

Instead of having the output like that, I would like to have it in matrix form, as in having this set of outputs placed in a larger set containing those sets as elements. This would greatly help me, as I would be able to manipulate and work with the entire output.