I don't think that 2+2=5 is a matter of viewpoints or opinions, and I don't see how correcting a factual mistake (or ignoring it) can affect your mental health and very likely corrections will be well received.
If instead you are talking of viewpoints or opinions, generally speaking the HN members seem to me quite civil, though there are more than a few topics (usually politics and related, but not only) that for some reasons whenever brought up seem to create very hostile reactions or however an adversarial environment.
If you stay around some time you will surely learn to not touch or comment on them (or be ready to receive downvotes and/or nasty replies if you do).
But on most topics, unless you are (needlessly) snappy or dismissive you shouldn't have problems.