1-I very much did feel happy.
2-I did very much feel happy
3-I very much felt happy.
None of the above work for me. I did indeed feel very happy.
I felt very very happy.
a- I did indeed feel happy.
and which means:
b. I felt very happy.
I guess they all mean you did indeed feel very happy; but they sound wrong.
If you want to emphasise that you did indeed feel happy, rather than the amount of happiness you felt (that is, you are defending yourself against someone who claims you didn't feel happy at all), you could say: I certainly did feel happy.
I did indeed feel happy.
Using "very much" tends to refer to the amount of happiness rather than to the strength of your protestations that you were, indeed, happy.
If you are insisting both that you were indeed happy, and that you were not only happy, but very happy, you could say: I did indeed feel very happy.
I can categorically state that my happiness was indeed far beyond the normal sense of pleasure that a man experiences when his life is absent the usual vicissitudes and drudgery of life.