You just have to let go of the need to be "caught up" or hear everything. Most podcasts don't really need that much continuity, so the need to listen to them ALL or even the idea of a "backlog" is just FOMO.

Think of it more like the old days of broadcast radio or TV. You listened to whatever happened to be on while you were listening and if you didn't hear something. . . who cares it's just entertainment?

Most of my podcast subscriptions I listen to only rarely. It's more like a shortlist of channels that have things I might be interested in hearing.