I completely understand how heartbreaking it is, to go through the death of your pets. I've lost two dogs, each of which I loved dearly. Losing them was harder than losing a human family member, by far. I think it's because they offer such pure, clean, steady love, day after day, without all the complications and ego that accompany human relationships. And because they're around us 24/7, they know us, and we know them, in a very deep and connected way. The love is profound and so is the loss.
How long it takes for you to move through the heart-wrenching stage of deep grief depends not so much on how much you loved your pet as what you think their fate is. If you think that's it, that's the end of it, they're dead and done, then I think that puts you in a much worse position for moving through the grief. If on the other hand, you have a belief system that includes a belief in animal afterlife and faith that you'll be re-united with them or even can communicate with them now, then you're in a much better position.
For instance, when I lost my first dog and my spiritual belief system was less developed, my intense grief lasted for a few months. But when I lost my second dog, my spiritual belief system was better anchored, and I moved through the intense grief in a few weeks. Don't get me wrong, I still feel a heartbreaking sadness sometimes when I think of her, which is often. But I don't have the intense, overwhelming grief anymore, because I know she's fine. I still talk with her. I know she's still around me. I know I haven't truly "lost" her, because that sort of love doesn't die.
My best wishes to you. I know how much you're hurting.