Hi THX1138, and welcome to PC.
I'm sorry you were served papers like that out of the blue. What a shock. I'm going through a divorce and it's very tough.
Because you have been served not only papers but a restraining order, you do need a lawyer to help you deal with this. Since you are hoping to still salvage the relationship, I would advise not immediately getting the most aggresive, hardass lawyer you can. Get someone a bit softer, who can litigate if necessary, but who understands you still are hoping to salvage the relationship. See if you can work with your lawyer and "the other side" to resolve the issue of the restraining order (that it is inaccurate). Your lawyer can also help you file papers to give you access to your kids.
Would it be possible for you and your wife to go to some counseling to get both of your feelings out on the table and find out what is going on? It seems like this is a possible route to reconciliation. At least you will know what you are dealing with. Your lawyer may be able to recommend a therapist who is good at dealing with separation issues like this and can help you and your wife work on communication and whether to stay together.
If your wife is suffereing from post-partum depression, she needs to see a doctor as soon as possible.
Take care and please post again. You can start your own thread down below if you wish.