When does it get easier?

My boyfriend and I have a 13 week old Aussie mix. We brought him home at 8 weeks, and it was really hard. In hindsight we were NOT prepared. He’s a wonderful dog and we love him, but today we got into a stupid fight over nothing, and I know it was in part due to the built up tension of dealing with the dog. We spend all our time watching him, playing with him, training him, strategically ignoring him when he’s whining... I know it gets easier, but WHEN?