Can I set a particular period to assess whether this marriage can be saved?

Setting a period for assessment can be healthy, because it replaces an endless deadlock with a clear goal. Instead of living in prolonged uncertainty, the two of you can agree to put full effort in for a period, then assess honestly. During that period, set out what needs to change and how it will be measured, rather than just waiting for feelings to change by themselves. This is not a bluff, but a shared commitment to try seriously. Involve a counsellor to guide the assessment so it is fair. Pray for guidance throughout that period. At the end, assess based on real change, not pressure or guilt. See counselling.