I'm so very sorry to hear about your sad loss, but please try and remember all of the good times, and the fact that the massive sense of pain and loss that you feel now, is a reflection of what a wonderful, valued and meaningful relationship you shared.
It does take time to heal, as we all know, and I like the others, still think almost daily about my special cat, who by now, has been gone for more years than we shared together. I still miss him to this day, but it just hurts less that it used to.
I agree with the other answers, don't rush to make any hasty decisions. I ended up having my boys ashes in a little casket with his name on, which resides safely out of the way of my current cats, as they would doubtless knock him over otherwise! I spent an awful long time considering what to do, as at that point, we didn't have a garden to place him in, and now we have, as he wasn't living here, it didn't seem right. It may possibly sound extreme, but for this boy, as he was my 'special' one, I have told my husband that I would like his ashes in with me if and when the time comes. I can't do it with all of my pets, but he was the special lad for me. Until that day comes, however long that may be, I just keep him in a safe place, out of sight, get on with my life, but know that he is still with me.
I pray that your pain eases with the passage of time, and just urge you to hold on to knowing how special it all was whilst you had him.
Plessy ( my boy's name, and used for so many of my usernames ever since, a nice way of continually keeping him with me in another way )