chin up Rob, every couple has their ups and downs, you can live with someone for years happily but marriage does change things in the relationship, especially the power dynamics, the adjustments that are required by both parties after marriage take time i think.
the daily grind of caring for kids and then work and housework and cooking etc can make both feel that they are giving everything and getting nothing back. Mutual appreciation is essential.
i think lots of us have been where you are at some point, i know i have .
If you have kids and are in for the long haul compromise is key and the ability to apologise, i found i had to do all the compromising and apologising for a long time before it became universal policy. Every relationship needs a peacemaker, the one willing to make the first move and hold their tongue. Choose your battles too, giving ground on the minor squirmishes gives you a better chance in the major campaigns.
Get out on the bike its a great time to think and get things in perspective, get a garage stocked with rusty bike parts and get along to a ride.
Sorry if this comes across as patronising, not meant that way at all. I ceratainly haven't got it totally sussed yet
and see you soon fella