I'm so sorry for your loss.
I always like to chime in with MY advice, since I had a bonded pair of neutered males in which one of them died suddenly and unexpectedly.
Since Baby died in my arms, and I of course was very upset and crying, sitting on the couch right in front of the cage, Mr. Whiskers could see that something was wrong. After a good, long cry, and a call to the vet to arrange to bring Baby's body in for a necropsy, I allowed Mr. Whiskers to come out and sit with me and sniff Baby as I told him what had happened.
I don't care if peoiple think that I'm crazy for anthropomorphizing my animals, but I SWEAR, I truly believe Mr. Whiskers was able to comprehend what I was telling him and that he understood that Baby was no longer with us.
Both of us were very depressed for some time, and I decided that we both needed another little chinnie to help us both recover. A few weeks later, My Little Snuggler joined us. After an appropriate quarantine and a VERRY slow introduction, Mr. Whiskers and The Snuggler are living very happily together as a bonded pair. It was necessary, however, to have The Snuggler neutered when he reached puberty, as he started picking on Whiskers.
As always, if you do get another friend for your male, you must have 2 cages available and plan for the possibility that they might NOT make a nice introduction and would have to live apart.
Give yourself a week or so to see how you and your boy do. And I'm serious, I think if you have some quality one-on-one time with him and explain what happened to his mate, it will help him.
I'll keep you in my thoughts and prayers.