My daughter and her husband lost his therapy cat in a freak accident a few weeks ago. That silly cat would have nothing to do with me, but he would salute my son-in-law and do all kinds of tricks for him. Favorite Daughter and her hubby were inconsolable.
Never let anyone try to shame you out of your grieving process. It will most likely last a good long while. Just roll with it.
Very sad story. (I think all cats are therapy cats! I envision petting them when having my blood pressure taken, and I think it might work.)