In the following response I will g-d willing address the Talmudic and Halachic discussion that follows, yet I must point out that being that this is a very sensitive topic one should not make only conclusion on his own his own rather must consult with a rav who knows him personally.
The discussion:
The Talmud in tractate Taanis tells us that Reish Lakish said a person is prohibited to engage in marital relations in years of famine for it is said “and to joseph were born two sons before the years of famine had yet arrived”
The explanation given is that one is to restrict himself from enjoyment while the world is suffering while others explain that it can cause weak children to be born.
The Talmud continues
Those who are lacking children may have marital relations during the time of famine.
(we shall address soon what this means)
Tosfot comments
Wasn’t Yocheved born to Levi when the Yaakov and the tribes move down Egypt during the famine?
Tosfot answers that this halacha is not a din rather a midaat chassidut Yosef was extra scrupulous with himself but other people did conduct during the famine marital relations.
Yet the Rambam rules as the simple explanation of the Talmud that one who did not fulfil the mitzvah of pru urvu of having children is to cease for martial relations at the time of a famine.
In the Shulchan aruch, the halacha is ruled following the opinion of the Rambam that there is a actual prohibition unless one lacks children.
A Additional discussion amongst the achronim is , how many children does one need to have for this prohabtion to apply to him? while some hold it means one child, the mishna berurah, rules that the question at hand is if one fulfilled the mitzvah of pru urvu by having a boy and a girl and practically speaking even if they have a few boys this restriction does not apply to them until they have a girl.
A additional discussion is there a allowance for mikvah night , the Shulchan aruch allows on the mikveh night while the magen avrhom is machmir.
The mishana berura adds that a person who has a strong desire and might have זרע לבטלה can be lenient ( this can be the reason why rabbonim do not make a big issue of this halocho knowing the situation of people in this generation).
Other tzarot
The Rama rules based on the Talmud Yerushalmi which I quote in the foot note that the same halcha applies to other tzaros as well. It is interesting to note that some achronim point out that the yerushalmi who broadens this prohabtion is only a din of hiddur as the Yerushalmi does actually not write forbidden.
There is much discussion amongst poskim how severe do the tzaros need to be in order for this halacha to apply to them as well some point out that it needs to be famine hunger related but not any other type of calamity or misfortune therefore a plague like covied 19 would not be included according to them.
Likewise halachic authorities discus the halcha at the time of war while some write as midas chasidus as the world is in chaos one should be machmir however others write that one need no be machmir as the restriction is to hunger related tzarros.
The mishan berurah comments in practice by other tzaros one can be lenient mikveh night although they have children.
In practice: in our current situation one can be lenient
