I've Smoked Marijuana Everyday Up Until This Past Week When

I've smoked marijuana everyday up until this past week when I was 18 weeks I'll be 19 weeks tomorrow. I have anxiety and fibromyalgia, im also a domestic violence survivor and I use to cope but I've also cut back tremendously. I've been drinking a gallon of water a day. I know using isn't safe and iam desperately trying to cut ties with that part of my life, I deliver in March I'm so terrified that I will not be clean by then even though I'm trying very hard to. I understand my kidneys have enlarged I'm a heavy set woman I weigh 245 I'm just concerned I won't be clean by March what can I do to keep my child I don't want my baby to be held responsible for my irresponsible choices. Any advice on what I can do