I want to emphasize that a sustainable average number of children per family is not zero [0] but around 1-1.5 for a sustainable population size in 100 years, according to the linked article. So given that you presumably live in a developed country (well educated, and don't need children for labour), and have a human's normal biological urges to reproduce, it's not immoral to produce children, but it's certainly not morally commendable.
[0] https://mahb.stanford.edu/blog/yes-overpopulation-problem/
I also think we should work towards preserving genetic material so in case of a catastrophe we will still have a diverse human gene pool.
This couldn't be further from the truth. I don't know anything about you but I can confidently say for every person like you, there are 5 that have a lot of kids purely out of inability or unwillingness to try not to. We are so far from not having enough children that your service to humanity is nothing but a stroke of your own ego. If you really, truly believed what you're saying, would you give up your right to have children under a guaranteed contract that someone else would in your place? Probably not.
I kind of want our race/country/planet to continue existing even if I can’t.