Seamless Composition?

Today was a fairly nothingy flat day! I was very aware of my friends absence as they flew half way round the world.
I just sat and marked books…
…
…until I noticed the light catching the tulips in the window!
I decided to have a little play with my camera, which was nice.

However…….trying to focus stack these photos so each layer shows the detail has been frustrating. Each section of this flower is in focus…..but I cannot get all the focused areas to show. Not automatically….and not manually. I haven't managed to work out how to use masking layers.  :/
I've lost track of how many attempts I've made now. Now I'm just fed up…and giving up! … (well….for now anyway!) :(