I accidentally stepped on my kitten and she died. :( am reeling from guilt and pain.
Have never had cats before but my husband insisted.

I have had dogs in my life and somehow I have never hurt a creature before..
Not that this was anything other than an accident, but its different-she is dead. :(

I don't know what to do...
After we buried her near her home in the garden, I thought I will feel OK.
But the guilt it so strong.

Has this ever happened to anyone before?

I have moved your post to it's own thread so that you can get responses to your particular situation.

Many of us have lost pets, it is never easy to deal with especially when we think there is something we could have done differently.
I take it this was pretty recent, it will get better with time.
Give it a little time, when the heartache lessens you could always put a small memorial in the garden for her, there are nice little stones that you can purchase or you could make your own. Or you could plant something by the spot where she is. Unless that is too painful for you. Personally I look at my stones and remember that pet fondly, but I will always miss them.

Thank you LadySam, your response was consoling

To add to the memorial part of grief, you can 'pay it forward' (it being guilt in this case) by getting another kitten in the not too distant future, and lavishing your usual love and care and tenderness on that one.

People who feel guilt over what they did about anything have all sorts of ways to make amends. You may not have to feel guilt, but you do anyway, so it's not really important how much of an accident something is. Work in shelters, donate time and support to organizations for animals. Drive around looking for lost pets you see on Facebook.

Guilt is normal enough, but it's self indulgent if we let it just fester without 'doing something' positive.