Nights drawing in

F

ell asleep while watching Sanditon with whole family tonight. Worrying as did not drift off to sleep on sofa as usual- slow fade out and noise vaguely discernible in background but one minute I was all buoyed up watching beginning of Sanditon the next woke up and it was over. Tv off – all gone out of room. Felt really bewildered. So sudden. So profound. Whats wrong?