No Judge can ever force you to be represented by an Advocate. But that's a strong accusation that you make here. What I suspect is, the Judge must be insisting that you go with an Advocate but he'd be doing so only to protect you from the repurcussions arising from lack of proper representation. Believe me, he'd have your interests at heart and no oblique motives; please don't be so antagonistic to the Court.
Even then if you are headstrong on pleading-pursuing your case in person go ahead and tell so to the Court in a strong, once and for all ,language. If a judge still insists, make an Application in writing under Section 151 of the Code of Civil Procedure seeking a prayer to appear in person and present your case yourself rather than through a pleader/vakeel/advocate; do not make any wild libelous accusations against previous advocates/professionals in general/Court; just state that you are fully aware of the facts and law and consider youself as the best person to present your case. I may add that no such Application is necessay; I haven't even heard of any such Application ever. But it would bring things on record of the Court that you made a concious decision to forgo representation by a lawyer. It'll also save the case from any future procedural defects insofar as entire case may be nullified if a party can prove that he was denied a chance of being represented by a qualified lawyer.
Just by the way, do you know the essential ingredients for proving defamation? Do you know how to pursue civil and criminal action against defemation in parallel? Do you know when orignal documents relied upon are to be placed on record? Do you know how issues are framed? Do you know how to mark exhibits? Do you know the difference between primary and secondary evidence? Do you know the difference between examination-in-chief and cross-examination? Do you know when facts not otherwise relevant may become relevant? Do you know how facts are to be proved? Do you know how to seek discovery and production of documents? And so on and on and on ad infinitum. Since you are raising a question like "does law allow a judge to over rule previous judge orders?", I can guess you won't know any of these either.
As much as [to you] Court may appear like a panchayat and Advocates just a bunch of monkeys with no special skills or knowledge, there is a reason why advocates train for years and there is a law on representation through advocates.