this is just my opinion, but if you aren't saying it like you are serious - then how do your coworkers know to respond appropriately? people say things like this all the time in the work place:

- i'm gonna kill myself if friday doesn't hurry up and come already
- i'm gonna kill (coworker Bill) the next time he....
- i wanna shoot myself in the head life sucks so much
etc.

people laugh at this all the time. people usually interpret it as letting off steam, they don't take it as something serious (e.g., they don't go alert coworker Bill).

i typically don't bring my illness into the workplace (apart from alerting my boss, should i need time off, or adjustments to be made). something like suicide is such a big and scary issue for most people, that even the people who love you most may not respond appropriately. i take my suicidal thoughts and feelings to my dr and therapist, and sometimes if i really need extra support, i will tell a few of my friends, who are well briefed in how my illness effects me and who also know how to support me.