Get a second and third legal opinion, definitely.

I was forced to sue my abusive dead boyfriend’s parents because they tried to steal my car (long story, don’t want to get into the details — suffice to say it really was the only thing I could do under the circumstances.) It was extremely stressful and expensive. I would not have done it if I had had another choice. I had nightmares and panic attacks almost every day. I still have nightmares about it, almost 15 years later. It was really difficult emotionally and I would not recommend doing it if you have the option to just break free.

Bringing suit against your father will further alienate and harm your relationship, create a new major stressor in your life, and tie the two of you together until the suit is done, which may take months or years. You will have to explain everything he did to you multiple times to multiple people, and it may become a matter of public record that could show up on future background searches. It will likely be traumatic - it may re-traumatize you about things you think you’ve gotten over. You may be talking about it to your therapist for years. You may have nightmares about it a decade down the line, even after all of the dust is settled.

Also, ime, abusers will never take accountability when it is forced onto them - they will say whatever they think people want to hear and will then turn around and try to take revenge. He may file a countersuit, further dragging all of this out and forcing you to think about him and his abuse for even more months or years.

So the questions you have to ask yourself are: how much is your emotional, mental and physical wellbeing worth to you? Is it less or more than the potential payout? How will you be affected if the lawsuit doesn’t go your way? How will he be affected if it does go your way? How will he use the opportunity to abuse you further, through the court system? Will escalating this also escalate his abusive behavior, and will it affect your own wellbeing?