I’ll try to state a case here related to the OP.
Op states
Here the OP is asking a direct opinion. So we can stop with all the accusations of being uncharitable and judgmental.

The OP is also acknowledging that they do not have serious reason to limit it to 2. I guess they could be mistaken about what classifies as “serious” but lets take them at their word.
Here we see that the intend is not to “space” but rather to make a permanent decision of not intending children for the rest of their lives.
Here we see that the poster may indeed have serious reasons (physical and emotional exhaustion) to avoid. But mostly in my experience we see someone who is focused on how they feel at the moment and not “big picture” and not aware that situations can and do change.
Here we see a glimpse of the OP’s worldview and frustrations. It was pointed out that many people can and do have 5 or more kids with less. Broadening the OP’s view of the world.
This is my favorite one. Not because it was obviously directed to me but because it shows the OP has an ability to be humble and not only that but to honestly look at this issue. It show’s a willingness to learn and to consider different views. That the OP thanks those who may be telling it without a sugar coating shows that they are more patient than I am and we could all probably learn from this example. Most people on the internet solicit a question and when someone gives an answer they dont like they freak out. Not this guy.
Wow. how refreshing, mature, and honest.
If I was the OP’s NFP instructor/counselor, I would tell them that this month is not the month to conceive. That they are overwhelmed at times and probably exhausted.
But I would also tell them that one of the great things about NFP is that it is a monthly conversation about the future you are forced to have with your spouse. This is one of it’s advantages over ABC. It forces the question to be answered every month. But I would also tell them that using NFP with the intent to NEVER conceive because they feel tired right now is not an intended use of NFP and could be grave matter and that they should
find a good and orthodox priest who is knowledgeable about this and seek spiritual guidance from them