What a drag... bad luck knows no bounds. Now what, check another method but there are not many methods, N/SN or maybe carbon monoxide, damn it.
Yes. Having a backup (Plan B) is always a good idea. SN will possibly become more difficult to get going forward (if you don't live in the US).
There have been a few high profile CTBs in the last year. One was just covered in the media just last week. I expect countries to either try and regulate SN at some point or more suppliers becoming more careful about who they sell to.
IC is still a reliable source but they too are feeling the pressure.
Carbon Monoxide is a good option but has logistical challenges and limitations. Can't be done easily (or safely) if living in an apartment/shared space with other people. Not everyone can physically go on a camping trip any time of year.
Many favour Fentanyl over CO2, but I can't speak to accessibility or method.