I can't save my world. please help me :,D

I think it started a week ago, but I just waited it out in hopes that it would fix itself. The problem is that when I click one of the upper buttons in Mcpe to save my world (this is not a server, by the way), nothing shows up. the save, options, and those kind of buttons don't show up. I'm forced to get out of MineCraft and quit it on my phone to play another world. In the side it looks like the buttons were about to come, but stopped before it can get part of it on screen. I'm just scared that the autosave won't get the last bits out before I have to stop playing, and if it gets too laggy I'd have to redo (minecraft)days of work.