The hubris of a 25 yr old (are you even married? Have kids?) telling middle aged people who have raised children your age or nearly so, when they should and should not have sex and how many children they need to have is remarkable. Honestly, I’m not sure if you are naive, or trolling.
Children are a blessing, yes. That doesn’t mean I can’t decide that I need a break from childbearing. Food is a blessing too! But that doesn’t mean I can’t go on a diet! Me limiting my food doesn’t mean I am selfish or think it isn’t a blessing. It means I’m being prudent. Same with me deciding “man, Hubby is looking hot tonight, but I’m ovulating and I haven’t slept a full night in 8 years, so I think I’ll just cuddle on the couch with him tonight instead.” That is NOT sinful. And you going AGAINST the teachings of the Magisterium, whom you as a Catholic should be obeying, and telling people it is is something you should discuss with your confessor.