I overslept totally and then at the morning I just said 'fuck it' and did it right, sleeping four hours more.
I'll give it another shot in few days, but I'm right now sick enough to just concentrate on healing.
One thing I have to think about is how to make sure I wake up on time. My phone's alarm has failed me before, it failed me now and it will fail me in the future. I gotta have a back-up planned.