Yeah, if nothing else works then go with what's easiest. I can't remember when exactly the lying down worked for us - there definitely were times when DS would just climb all over me. I think maybe I held him and sang, then lay down once he was drowsy. Then after a while would go straight to lying down. And so on. God it's all a blur.
I slept on a mattres on the floor with him most of the time 8-18 months (we had the odd good week when he didn't need me). So gave up on the cot, yeah. And when I night weaned at 14 months he just started asking for food because he was hungry . Sometimes you just can't win.

DS didn't learn to self settle at all till nearly 2 and still needs help most nights (but somtimes sleeps through now at least).