There could be lots of reasons including, rather peversely, getting better. There is a lot of evidence that shows there is a high risk of harm during the recovery phase, probably because of the increased ability to motivate and carry a plan through to its conclusion rather than the "meh too much bother" apathy of a deeper depression.

Hormones were/are still a major trigger for me, now I get the more usual moody, tearful anger that is normally associated with PMS, but when I was younger (teens through until my mid 30s) I got into intensely suicidal rages.

Alcohol is a trigger for me, and avoiding alcohol has been one of the biggest breakthroughs I made in staying safe. Apart from one or two binges (lifestyle, self harm and experimentation) I never really drank that much anyway, but I realised that even one drink could make my mood plummet if I was vulnerable that day. I'm not tee total and sometimes have a drink even now but I don't enjoy it much.

Keeping a diary to identify patterns and triggers might help. Until then, try to keep distracted and find someone to talk to or just be with. Can you get your boss to change how your work is allocated so your tasks come in at the end of a working day ready for the next day? I totally relate to the clear desk thing. Back in March I cleared my desk for the first time in months. I sent out a report, logged out of the computer and the next day called in sick, I've not been back since then.

Take care.