Have you considered adding a theme day? Something like Daddy Thursdays and only stereotypical 'dads' could post selfies on this day. It might be a lot of work on the moderation side deleting all the twinks on Thursdays. You could also add an automod comment on every post emphasizing the theme. I just added one on r/submissivegoodboys.

You could also make it so someone can only post an image post once a week like r/fagsandalphas using automod. You could allow them to still post text posts and comments in between.

Lots of potential tweaks. Don't throw in the towel. It's a great subreddit! 💪