Yes, that the last thought moment determines the next birth may be quite unsettling.
However we must not forget that in many suttas it is also said that observing the 5 precepts and living a moral life leads to heavenly worlds; BUT in one other (at least) it is stated that even given that, one may still end up in a lower bhava, depending on precedent or antecedent causes. I do not remember which sutta that is. So is there anything we can do about it? This is the question.
If you have eaten sausages the whole week for breakfast, it will be the thought of sausages that comes to the mind at breakfast time next. So constantly living by the Dhamma makes it more likely that we are in that state at the moment of death. But still there seems to be no guarantee.
The guarantee is this: those who have gone for Refuge in the Buddha, Dhamma and Sangha, i.e. even before attaining the Sotapanna Stage, are ‘exempt from places of loss, the animal realm, hell..” That in itself means that one will not GRASP a thought (if it were to arise), an arammana, that leads to those places.
