Upvote:2
They already have the information about your past refusals in front of them, of course. Although you withdrew the application, you did still make the application in the first place - you signed it and everything - so this is still likely a “false information” case, and not something you shouldn’t mention. Bringing it up gives you a chance to explicitly say it was a mistake and to point out that you voluntarily withdrew the application.
But do not take that advice; it doesn’t matter. Applying again after a second refused visa is not a DIY situation. You should be contacting a REPUTABLE immigration attorney (not a “service”, not an “agent”, but someone who is officially licensed to practice UK law). They will advise you on the best approach, which (depending on the circumstances of the previous refusal) will likely include “wait a few years first”.