I am thinking about divorce after only a yea a half and have a newborn?

I live in Louisiana and am thinking about divorce. I just gave birth to abeautiful little girl a month ago. My hsand and I have been having prolems for a while i just kept making excuses and telling myself it would get better. We have had any many conversations to try and resolve the problems but things always go back to normal and now that i have our little one it is hitting me harder. I feel like a single mom because i get NO help from him. He only seems to help or do anyting other than play video games online & chat online when he wants something from me. I do love him but I just don't think we are meant to be any more. I want to stay civil but if I go though with this I am afraid that when he has his time with her that she will not get the attention and love she needs from him and am afraid she will get hurt. Because I know if I go through with it, his gaming will get worse and thnk he will drink and party more like he use to. I guess I do not have just a question I need some legal advice as to what to expect with a divorce involvng such a young child and how custody will play out.