To keep going or find another way.

In my opinion, I would stick with that person. There's always a reason why there's no spark anymore. Probably most of the time there's a 3rd party included but just give it time. Give some space if needed but hold on still until you both decided it's not worth it anymore.

The fact that you even have to force yourself to get somewhere is a dead giveaway this ain't going nowhere fast. Can you really see yourself spending the rest of your wearing a mask of someone you're not? Either it will breakbeat or you will, but this is no way to live imo.