Grieving is important it is your personal time of saying goodbye, our 'sophisticated' cultures lack the group rituals of more 'primitive' societies, and we have lost the connection to the importance of this time.
Grief is personal to all of us, but it is important to go through the process, and then to move on when you are ready. Some people don't get it, "It's just a horse" and other such rubbish, they are the sad ones, because if they have never loved a horse like you loved Indie, then they have missed out on a beautiful experience.
It is equally important to move on when it is time, you cannot bring her back, but you can celebrate her life by starting to live yours again. I know what it is like to lose one, I lost a little colt who took such a huge part of me with him when he passed, I thought I would never feel joy again, but I did, I mourned him, but gradually I started living again, I will never ever forget him, of the feel of his head pressed against my chest as I begged for his life to be spared, but it was not to be.
Truly I believe that the only thing worse than the pain that you are feeling now over your loss, is the emptiness that you would have if you had never loved her.