Ok, now for the legal side. First a disclaimer. I am a US lawyer (with no knowledge of international law) and am licensed in four states (but probably not yours). I don't practice family law (although I did some work in family law early in my career). It would be malpractice for me to give you legal advice if you are in my state and I haven't met with you and gone over all the particulars of your case with you before dispensing advice. It would be practicing law without a license for me to give you advice if I am not licensed in your state. However, I'm going to respond to some things I have seen going on here and on other boards. Keep in mind, even if not expressly stated and repeated each time, my first comment to you is to seek an attorney who practices in family law where you live and can give you appropriate advice based on your facts and the legal issues and local practices affecting your case.
1. Please, talk to an attorney. Family law varies by state, it is not a national practice. Family law is concerned, when there are children involved, with the best interest of the children. This is a fact-specific inquiry. Each case is different. Each court has its own local rules that it follows. I am an attorney, but I have an attorney. I've read every statute and case affecting my situation, but I still need to discuss how local courts will apply these things. I had to prepare and file a motion in my case. I read all the statutes and the black letter law, but I had my attorney help me add things the court would want to see and remove things they would not.
2. I am more fortunate than most in that I have the means, at the present (remember things can always change for any of us), to pay my attorney. I also have the ability to do a lot of the work myself to keep costs down. Those are a given, but even those of you with limited means may have situations that absolutely require that you at least consult with an attorney or have them review your agreements. Those situations are things like custody disputes, property (real estate, inheritance, pension/retirement plans, automobiles, household goods, you name it), and safety issues (stalking, protective orders, etc.).
3. If you and your spouse have limited means and no kids and no property and haven't been married long, contact your local courthouse. They may have a clinic or a statutory framework for a simple divorce.
4. If you are living within 150% of the federal poverty guidelines (which you can google), you can likely get some kind of legal aid to help you. Check with the court, call your local legal aid offices, etc.
5. Many areas will have pro se clinics (this just means you are representing yourself) that will walk you through the process. Legal aid clinics will often also have those.
6. If you do not have a simple case and cannot afford an attorney, then scrape together what you can and at least consult with them as often as you need to. I am not advocating employment for my family law brethren here. I am trying to bring home that this is not something you can do without guidance. If you have property in dispute, then you must, must, must speak with an attorney to ensure that you are adequately protecting your interests.
7. Family law is not like regular civil matters. If someone sued me for another kind of case, no big deal, I can represent myself. Family law is different and you must speak with someone who not only knows the laws but understands how the local courts will interpret them.
8. Many states are no fault. They don't care how many times your spouse cheated or that you put the toilet paper on the wrong way. Affairs are generally not relevant (but I do know of at least one state that is no fault where bad conduct may be a basis for an unequal distribution of property, so ask your lawyer) and you sound like a lunatic if you keep talking about them.
9. If you have a mentally disordered spouse read the book Splitting. It talks about how courts don't like it when you come in and talk about your mentally ill spouse (whom you and your counselor have diagnosed). Talk about the behaviors and how they affect the kids and leave the diagnoses out unless they have been diagnosed by someone who has actually met with them.
10. Most of the jurisdictions I am aware of will give joint custody unless the other parent has harmed the child. Therefore, your belief that your spouse isn't a good parent is not enough. Yes, they will give some custody to parents with problems. In my state I can ask for a deviation based on certain factors which are expressly enumerated by statute. These include things like diagnosed and documented mental illness, diagnosed and documented drug tests, abandonment, certain criminal acts, an abusive use of the court system, etc. Unless you have something pretty egregious you will not get sole custody with no visitation and asking for it can make you look unreasonable. Again, talk to an attorney about your situation.
11. If your spouse has documented problems, think about requesting drug testing, review of mental health or physical records, etc. In my state, anything goes. I can get any information as long as it has some relationship to money or the kids. But, if I send discovery requests on everything, I'm going to get them back asking the same things for me, I'm going to spend a lot of money (discovery is one of the most expensive parts of a case), and I may learn things I can't unlearn about my spouse if I have any hope of reconciliation in the future.
12. Why would you want to keep your child from the other spouse? Your relationship with them is not the same as their relationship with the kids. Even the children of convicted murderers pine for their parents. Your children will forgive them for breaking up the family and leaving. They may not forgive you for trying to keep the other parent away or for badmouthing. No matter how wronged you feel or how much you dislike them right now, they are your child's parent, your child loves them (even if they say they don't), and you don't want to harm your child.
13. States differ in how they handle parties living together in divorce. If the situation is bad, you may be able to request a kick out order. Talk to your lawyer.
14. There is a prescribed flow for how these cases go and the order in which things happen. A lawyer can explain the process to you and when and where certain issues get raised. Remember to that you are creating a public record that can be accessed by others, including your children later on. I recently talked to someone whose parents divorced when she was young. She said they would ask her questions, which would then turn up in pleadings and the other parent would get mad. To this day she doesn't trust either of them because of this. Don't put your children in the middle, ever, in any way.
15. I think judges in family law cases are used to seeing unrepresented parties; more so than other areas of the law. If you have to do it, you have to do it. Read up on the practice. Read the statutes. Consult with an attorney as often as you can.