One Lone Angle :(

Hello, I have a single, adult angel fish in my 38g tank. He's completely alone now, since the last of his tank mates, Martha, a female silver dollar, has died. No other angels, and no tank mates whatsoever. :( I've read that I should not put smaller angels in with an adult, and should be quite careful with even adding larger angels. Should I leave well enough alone and not add any fish, or should I add some buddies for him? Being the human I am, I worry he is lonely :(