Am I doing SMN wrong or is there just a LOT to do?

[SchrodingersWaffle]

keep track of your DWT/FBT, make sure to cast Deathflare before DWT expires (yup...what you think has happened me a few times...).

I've had a couple times where I've VERY CLEARLY cast it with 1s left on the clock and it tells me it can't cast. It's pretty annoying with so much crap going on.