Sorry, but not leaving him because he would demand 50/50 access and when he gets another partner, your daughter would have to deal with his abuse unprotected is false thinking
Currently your daughter is experiencing 100% of her life living with an abuser, assuming that a situation where one partner abuses the other mentally is love and is normal and that women should always be subservient to men
Can you not see that you are already doing far more damage to your daughter than the other scenario you describe. You do not even know whether he would get 50% access. He is an abuser, courts now look on abusive men much less kindly than they did. Him demanding it is not the same as him getting it and is your daughter not entitled to spend at least half her childhood in a normal household so that she can see, and quickly tell the difference between the two?
Your whole description of your life is written from the perspective of someone who has been worn down and completely cowed by their partner and is justifiying her current passivity by pretending that it is her choice, better for her child etc etc.
You know very well indeed that your life is not a life where you have rationally decided to stay with your partner. You are staying with your partner because you are too scared of what he will do if you leave.
However you have posted on GN and I think that is because in your heart of hearts, you know that you are in an untenable position, that you are being emotionally and psychologically abused and most of all you know in your heart of hearts that your current life is bad for your daughter and staying in it could do untold mental and psychological damage to your daughter and could damage her ability to negotiate a safe and loving relationship for her self for life. You have looked to us for advice and the advice we have given you is unanimous - GO
What you need to do is make contact with a Woman's Aid or Refuge, an organisation that can help women in your position, help you, not only in providing somewhere safe for you to go to, but also legal advice. There will be one locally, it will be accessible online.
You could also go and see a solicitor, make sure you go to a good sized company and ask to speak to a solicitor specialising in family affairs. You could also seek advice from Citizen's Advice. They too can tell you ways you can safely leave.
You are in a seriously abusive relationship, that could destroy your child's ability to lead a happy life. Currently you are worn down by your husband's bullying and have justified not taking action by pretending it is your independent decision to stay. It isn't, it is a decision made by someone exhausted by abuse.
For your childs sake. leave