So that is like 'unicorn'. the word is in every dictionary (I assume), even the concept exists (there are stories with unicorns in it). But unicorns do not exist! Same with your definition of free will: it might be that such a definition exists, that there are (philosophical) stories woven around it, but that doesn't mean that it reflects some aspect of reality. And so here I am fully with @iNow:
If your actions would be 'independent of any previous condition', they would be absurd, having nothing to do with the situation you are in.
Here you seem to contradict yourself: I more ore less read: 'sometimes decisions "uncaused by any previous condition" occur, which means they are caused (conditioned) by previous conditions". That makes no sense.
So free will is always a "conditioned" free will: conditioned by external circumstances, but also by your own (true) beliefs, values, motivations, reasons, etc. And if you can act according to them, your action is free, so you have free will.
Change of personality is not an obstruction of free will.
Both Dr Jeckyll and Mr Hyde can be free in their actions. The free will lies in the relation between your personality an your actions. You cannot choose who you are, but you can choose what to do. The decisive criterion is if you recognise your actions really as your actions: they are according your own (true) beliefs, values, motivations, reasons. How these are implemented in your body and causally lead to your actions is not a decisive criterion.
Maybe Dr Jeckyll does not recognise Mr Hyde's actions as his, because it really was another person.
The point with my definition of free will is that it fits to our experience of free will, has (nearly?) no 'metaphysical ballast', and is not in conflict with determinism (quite the opposite!). It doesn't suffer from the conceptual inconsistency of "uncaused by any previous condition", or 'being able to do otherwise".