I am also hoping best possible outcome is get released by your companions if not released by Mythal or Dreadwolf themselves with your companions finding a way to undo it because the alternative from my perspective is your no longer the main protagonist anymore if do not, your relegated to the role of similar to Calpernia and Samson (secondary antagonists) with them being just a follower/controlled by Cory (main antagonist) only this time you would be (secondary protagonist) controlled by Mythal (primary protagonist/antagonist) in my opinion if do not break that link ASAP given your not just influenced by Mythal as shown in game she has complete control over your actions when she wants to do so.
If Bioware have any sense they will break this link in the first DLC for the game because if not the player or at least myself will feel like it is no longer my character or that I no longer have full control/faith in my own character and his or her decisions, I could no longer trust that my actions are mine alone and not that of Mythal from an RP perspective regardless of whether or not I feel choices make are the right ones during that period of which is bad game design despite being an interesting plot development.
If a player does not feel like the character is his or her own anymore, we end up with a similar overall outcome to DA2 and Hawke, lack of player agency and disbelief that you have control over your character and events around him or her being shaped by the players choices and not someone/something else with you just along for the ride. You need to have that trust in the actions and choices of your own character in game but being under Mythals control you no longer have that trust, that your choices as a player that you make from an RP perspective is yours and not played off in game as Mythals choices through her control of your character.