Don't push yourself until you feel ready. Don't feel guilty either, it's still so soon and there is no rush. We all know how much you love him. It'll be hard enough reliving the events in your head without writing them down and seeing them in black and white. It makes it more real somehow. Like if you don't write it, it's not real. But to write it means you accept he's never coming back and that acceptance is hard. You know he's not coming back, but some part of you still hopes for it.
I reread Dexter's tribute last night which I did for him a few weeks ago when I joined the forum and I cried buckets as it brought it all back. So hats off to you for thinking about doing one already, I was too busy blaming myself for months after Dexy passed. Then I read the other month an article that made me think I could have saved him if I'd gone to another vet or asked for a second opinion or something, and that ripped the scab right off the wound.
I think when you lose something you love so much, it creates a hole in your heart that can never be filled. It scabs over, but never fully heals and it's easy to have it ripped off again. But your heart gets bigger so although that particular hole is not gone, you are still able to fill the rest of your heart with love for something else, like Bisc in this case. It's not like that game children play with a wooden board and have to fill the round hole with the round peg and the square hole with the square peg etc, because the only thing that can fill that hole is temporarily missing in your life. The peg is lost, but the board keeps growing for you to put in new pegs.
I really hope this helps you. Everyone experiences it in different ways, but I'm drawing on my experience with Dexter, you may be completely different. I don't want to make things worse for you, but I have so far only ever lost one thing I ever really loved heart and soul and two years later, it still sneaks up on me and I can't talk about him to people as I still cry. The only place I can talk about him is here, which I find therapeutic, even though I probably talk about him too much. So I don't want to say, it won't ever hurt because it still hurts me and I don't like lying. I really hope this hasn't made you feel worse, I have a tendency to put my foot in it
but I wish I'd had someone there for me when Dex died and so I'm trying to make sure you don't feel as alone as I did.