Thank you for the excellent description, AGlassOfMilk. I'm fairly certain this is the same issue reported by another player who managed to ram themselves all the way outside their FOV.
Ramming and displacement does not update your FOV, an oversight that is getting players who do a lot of ramming in tunnels stuck in places where the game no longer lets you move since you aren't allowed to move through non-visible spaces! So I believe you're stuck in the tunnel here, not a wall, and there's no way to get around that
For the next release I'll be both updating FOV on ramming/displacement and adding a failsafe so that
just in case I miss something in the code, the game will always make sure you can see yourself and if not update FOV immediately!