Anjy, no - don't change the subject next time it happens. If you do this, she'll keep raising the discussion. Instead, make it clear that you will only like and comment on photos which are particularly relevant or interesting to you. If she argues, just let her know that this is your position no further discussion will be entered into. If she keeps at you, go home.
For what it's worth, I'd also find it really annoying if my hubby liked and commented on every post which I did too.
Never regret anything that has happened in your life. It cannot be changed, forgotten or undone. So, take it as a lesson learned and move on.