If by time off you mean doing nothing, then yes, that's way too long. When I coached cross country a while ago and I would encourage runners to keep it up in the summer, I offered two maxims: 1) it takes twice as long to recover as the time off, and 2) it's easier to stay in shape than to get in shape. By that, then, I wouldn't be surprised if 1) it took you 12 weeks to return to the same form, and 2) it's gonna hurt getting there.