Yes get him a friend. Contact your local rescue. Age is not the important factor but personality. Was your boy the boss? If so you want a laid back friend for him and if he was not the boss then you want a dominant pig.
I have very successfully matched older boars together based on this. I insist that this is done at the rescue and i watch them for hours to ensure all OK before sending home.
If there is not a suitable piggie at the moment, do your rescue offer the "lone a piggie" service?
I lend a piggie and a single hutch to enable them to see, and talk to each other so there is some company until a suitable friend is found in some cases to ensure piggies health.
Where abouts are you?