It is ok and not at all inappropriate to seek help here.
I think it is. We are not suicide experts, we know nothing about how to help, and our attempts to help can easily backfire. And this is assuming that we are not being trolled, attacked, or drama queened (anyone can say that they have contributions under another account). Let us recall that pdf23ds asked for LW help with his sleep problems which did nothing, and LWers attempting to follow up on his posted suicide note apparently did not solve the problem.
The big sites like Wikipedia generally have a policy of:
I don't see any reason that this should not be implemented on LW as well.
We are not suicide experts, we know nothing about how to help, and our attempts to help can easily backfire.
This sounds to me like taking the precautionary principle too far. Shouldn't we do an expected value calculation? I imagine the folks at Wikipedia had a few incidents of people being helped with their depression and killing themselves subsequently (possibly as a result of the help they received), then Wikipedia was like "What should we do? How about a don't-talk-with-suicidal-people policy?" without looking at the other, much more obs...
If it's worth saying, but not worth its own post, even in Discussion, it goes here.