Tiny Tuesday - rhododendron and ant

I know it's got to be Tiny Tuesday, but I don't know the number.  In the 70's somewhere.  And with a bit of research I've discovered it's TT72.

Anyway, late in the day - the rhodo is struggling to bloom this year, although you'd think it would like the cold and wet.  Come to think of it the rhodo is struggling full stop.  It's been fed, watered endlessly, and I've put some acidifying stuff on the soil.  I don't know what else to do.  That's my mystery twist - how to I make my rhodo recover?