Thank you for your reply. I am sending this answer to you only a few minutes after you submitted your question.
It sounds like quite a bit has happened and you will absolutely need to retain an attorney to represent you. You said that most attorneys won't touch the matter because a mess has been made. If that's the case, you may have to shop around to find an attorney who will represent you. It may cost more as well due to the complexity of the issue. However, if it's that much of a mess, you're not going to want to represent yourself. Most laypeople can't represent themselves well even in the simplest legal matters. Therefore, with highly complex ones, legal counsel is that much more important. If you cannot afford counsel, you might want to contact local legal clinics to see if they can help. With custody and visitation matters, it's necessary to show that the proposed modification is in a child's best interests. With child support, it's necessary to show a change of circumstances justifying a modification. Custody modifications, income changes of either parent, etc. could support a child support modification.
If the previous attorneys messed up your custody matter, that could provide a basis to sue them for malpractice. That wouldn't change the outcome of the prior matters, but it could provide a basis for financial recovery. Further, if the attorneys have made misleading statements regarding representation, bill collection, etc., that could also provide a basis for a complaint to the state bar. If the state bar finds that they have deceived you or otherwise acted unethically, it may sanction them for their behavior.

Sir,
That's not at all what I said. But first, please understand that it's not possible to retain an attorney here. As is made clear throughout the site, JustAnswer not a substitute for retaining an attorney.
I certainly understand your hesitation to retain new counsel and I certainly understand the expense. However, if you want to seek a modification to custody/visitation orders, you're going to need one. You've described your situation as being so muddled that even other attorneys won't touch it. If that's the way it is, it's extremely unlikely you'd stand a change if you chose to represent yourself. As you have seen, the law is confusing and it's just not something you can just pick up and handle. So, while you could try to represent yourself (a court might allow you to appear using the telephone for some of the court proceedings), it would simply be unwise and you probably wouldn't come out of it very well.
Men often do have a disadvantage in custody or visitation matters. There are a variety of reasons for it, but the truth is that the law doesn't always bring the right results, particularly if there's a disparity in the quality of representation. That's why, if your attorneys failed to act diligently and professionally, there would be a basis for a malpractice lawsuit against them. The state bar and malpractice liability generally compel attorneys to do the right thing and handle cases responsibly.
In any case, if you want the justice you've described, you're going to need counsel. You need an attorney to represent you if you sue for malpractice. He may represent you on a contingency basis, meaning that he receives a percentage of the award if you win and he doesn't get paid fi you lose. You also need an attorney to represent you with any custody/visitation modification proceedings.
I know this isn't fair. However, you do need counsel. You can try to represent yourself. However, doing so just isn't a smart move because laypeople generally are not able to competently represent themselves due to the complexity of the law and legal procedure.

That certainly does sound unlucky.
A letter to a judge wouldn't generally be enough. To modify custody/visitation rights, a parent would need to file a petition. That said, the new judge should review the matter in light of the child's best interests and enter an appropriate order on that basis. Therefore, if the other judge didn't rule on the facts or if today's facts justify a modification, the new judge may grant it. That said, you still would want legal representation for the matter. It's worth noting that attorneys realize how costly their fees can be. You may be able to use a credit card, negotiate a lower rate, or work out a payment plan with some attorneys. It's up to the particular attorney. However, some may work with you on that matter.

For a variety of reasons, it's not possible for me to provide direct referrals in this forum. However, I can provide you with some great resources that you can use to locate an attorney. Lawyers.com and Martindale.com are great resources. Both of these sites enable you to search for an attorney based on the attorney's field(s) of practice and geographic region. You would be looking for an attorney who handles family law and another attorney who handles malpractice (if you wanted to pursue such a suit). You may even be able to find a firm that handles both issues. Additional information about an attorney may also be available on those sites (links to the attorneys' websites, reviews, etc.). That information can help you to evaluate the attorneys. The Florida Bar's Lawyer Referral Service provides similar search tools. Before retaining an attorney, you may want to inquire with the Bar about his or her disciplinary history as well, as that may tell you something about his or her ethical standards and behavior.