You poor thing.
Breath in and breath out real slow. Do this a few times.
What I do when I am stressing and freaked out is make a list.
A list of things I need to get done in order of importance.
This will guide me and keep me focused.
Next to each item decide if you need help. If you do, see if you can figure out who you can call on for help. Email or call them and say SOS.. I really need your help.
The inlaw situation is just drama. Drama you do not need so let that go. When your husband gets back let him deal with it. Do not make a big deal that they will not be at daughters party, just go on.. I have learned that just indifference with people takes away their power over you. They want to hurt you, by punishing your daughter, but in reality, they are the ones missing out. You r indifference will cause a lot less stress.
If you do not feel up to going to court, call the court and explain how this will be burden for you 37 weeks pregnant, next week, with 2 children and no childcare.. Maybe they can just get a statement from you instead. Maybe your doctor can write a note that you are too close to delivery and your blood pressure is already too high.. or whatever is going on with you..
I like a nice warm shower, then I use a sound machine to try to relax, I like thunder storms, so I put that sound on. .. or I play soothing music.. I wear an eye pad... And I just plop on the bed and think of a dream I want to participate in..
And do not go crazy on this party.. Keep it to the basics. The kids will enjoy just playing and Cake and ice cream is enough food. If you really feel like you need food. Order pizza and ask them to slice it in smaller slices..