Watching the interview and looking back on the history of how he became Batman, the low point seems to be a result of everything going wrong and not having the power to fix it.

Affleck only took on the role after being convinced by Snyder (after Daredevil he was reluctant to take on a superhero role again). Batman v Superman was rocky, but a future solo film was planned. Then Justice League happened. Massive studio interference. Snyder had to step away and lost the film. His costars had issues with the new director (Whedon). And of course Affleck had his own personal issues.

To be Batman, but not feel like Batman, I get it. That would suck.

I doubt we'll ever see Affleck as Batman again. Who knows. Maybe an old Bruce Wayne in 10-15 years as part of a future Flash storyline.