I am in the same situation.But,my children are now grown.Supposed to file on monday.What does your heart tell you.What are the reasons you'd choose working it out? What are the reasons for not wanting to?

I understand the resentment eating at you.Is sounds as if the relationship is currently toxic.

How much of you believes he really could change?

Then,of course there is your child to consider.And the child comes first actually.You were happy apart.Happy is healthy for the child.The child will never get their youth returned,and these formative years are crucial to the emotional health of the child and the relationship example.And try as we may...to hide the tension etc,the children are like radars for emotional atmosphere.I think the child needs to see one of two things.

Mind you ,I am pretty dysfunctional my self,but,my thoughts are....
1: Mom in therapy working through any existing issues,and moving on in as healthy/productive a manner as possible...and not involving the child in hearing negativity about the dad.....because it will manifest as the child reflecting on themselves."Maybe I am just like him" ,"If mom doesn't like/love him she may leave me if I am similar in any way"

or

2: Mom and dad in therapy with sincere intention of working through,still not involving the child in the adult issues of the marriage.If you feel that your interaction,during that time will impact the child,then the child needs to either be in therapy,or you two need to live separate while working through.But,imo....it is the child that matters most.How you handle this will impact him/her for the rest of their life.It will be an example of how to handle emotion in a healthy manner,and will cause the child to mirror what they see.

A link that may be helpful is http://www.helpguide.org/mental/children_divorce.htm

I would sooner consider the link,than I would consider my personal views.May you be well,and healthy.