I have to admit that I have never heard of such a situation. Without going into the who's and why's of waiving speedy trial before an information is filed, it appears that you are in need of a criminal defense attorney. The situation that you are in is unique and problematic. If speedy has indeed been waived, the state will now operate under the statute of limitations which could give them a very long time to file, depending on the charge.
I strongly recommend that you hire a criminal defense attorney to assist you through this situation.
I, like the other attorneys, have never heard of something like this. If this situation occurred as you have described it, it scares me that someone would request you waived your right to speedy trial at a point it was not necessary to do so and that you waived this right without speaking with an attorney first. You are right when you say that you could not file a demand when there has been no information filed, because the case is not ready for trial and no attorney could be prepared. I would immediately consult with an attorney. You need to be proactive about this in the event that you can salvage your rights. Moreover, you need to ensure that no more of your rights get waived.
Sounds like you should speak with a criminal defense attorney who can look at the specifics of your situation. If a valid waiver of speedy trial was filed, the State has until the statute of limitations has passed to file charges. You are correct in that filing a "demand" for speedy trial includes a certification that you are prepared to go to trial on the case. Whether or not the inital waiver was valid would be a question that would have to be answered by an attorney that had all of the facts and circumstances in front of him.
I also question how there can be a waiver of speedy trail a few days after your arrest. A lawyer may be able to review your specific situation, make a determination as to whether there was a valid waiver of Speedy trail or not and then hopefully take appropriate steps to remedy the situation. I would encourage you to consult with an attorney regarding your situation.
A demand for speedy must be filed after the filing of the information or indictment; if it is filed before the charging document is filed, it is a nullity and will have no effect on the time period set forth in the rule. State v. Hill, 313 So. 2d 766 (Fla. 1975). The consequences of filing a waiver of speedy trial can be broad and severely prejudicial to the client. In the absence of fraud, the acts of an attorney in waiving speedy may bind his or her client even if the waiver was done without first consulting the client about such consequences. State v. Abrams, 350 So. 2d 1104 (Fla. 4th DCA 1977). You might want to consult a creative and thoughtful criminal defense lawyer who could consider all of the facts of your case which would be needed to more fully address your issue.