Yes, it is all right to start and stop the forgiveness process if you feel that you need a rest from the challenges of forgiving. As an analogy, if we want to be physically ﬁt, we do not work at that ﬁtness 10 hours a day every day. We need to be more temperate than that. So, working on forgiveness for an hour or less some of the days of a week seems reasonable to me. Taking a week off is ﬁne. I was asked by a person if she could take a year off of the forgiveness process. This, to me, would be similar to taking off a year of physical ﬁtness training. One likely would get out of shape waiting that long. One probably would get out of forgiveness-ﬁtness shape as well waiting for a year.
For additional information, see The Four Phases of Forgiveness.