Great concept and well done for getting out a working version!
This was my first 48-hour jam and I found breaking the development into equal sized time-blocks helped. In my case I scheduled 3-hour dev sessions with 1 hour break in between and two full 8-hour sleep blocks. This gave me 8 full sessions in which to complete my game and I planned out what I thought I could reasonably achieve in each (even though I didn't necessarily manage to achieve it all). I feel the regular breaks and sleep helped me be more productive and enjoy the process. One other thing that helped was making sure that at the end of each session I had a working build so if anything went wrong I would always have something to submit.
Sorry for the unsolicited advice, but I hope it helps.