'Doom' actually means either 'fate' or' judgement' (as in a legal or court judgement). It's like that other term , 'weird', which also originally meant fate or destiny.

In which case, doom cannot be avoided. What matters is how you meet it. To refer to Tolkien again, Beren met his doom with courage and grace, and was granted a second life with Luthien - they founded a Line of Kings that stretched from the First Age to the Fourth. Turin fled from and denied his doom, and died alone, childless, by his own hand.

That is the secret of free will. Your doom, your weird, cannot be escaped. But youcan chose whether to flee, hide and grovel, or to meet it with head held high.