How would you cope with an ailing friendship, when you are unsure of whether you should hold on? Letting go seems like you are not trying to hold on hard enough, but holding on might make things worse.
Time heals all wounds, they say, so I would advise backing away and letting some space develop between you to see if the friendship has any ongoing value. If it does, you’ll both find yourselves coming back together in a stronger relationship. But if it doesn’t, you’ll both feel free to move on, and neither party will nave been hurt.