Firstly, well done on your first lucid.

Secondly, I haven't experienced that before (seeing as I've not had a proper lucid before), but I have experienced times where I've known I would wake up if I simply lay back. Often this sort of thing would happen in a primary school dream where I'd be sitting on the floor with the rest of the class (I think it's a British thing), feeling uncomfortable, before I realised that my real body is lying on a comfy bed. I would then be able to simply lie back and feel my bed and either wake up, or transition to another dream.

Unfortunately, I don't have any advice, just thought I'd share my similar experience.