Is there any idiom or expression that would mean "all my efforts wasted"?

I'm looking for an idiom or expression that would mean "all one's efforts wasted".

I have found "to have one's cake dough". Can I use it for "all my efforts wasted" too? ( A non-native friend told me it is used for saying " all 'my plans' failed", not 'my efforts'.)

I want to use it in:

John spared no efforts to provide his son with anything he needed for going to a medical college, but his son disappointed him by going to an art college. John accepted his son's choice but was really upset and felt ----(=all those efforts were wasted).

PS:

In Persian we say "one's yarns changed back into cotton".

(You know that cotton is changed into yarn by spinning, using a spindle, that takes a long time and efforts, so "all my yarns changed back into cotton" means "all my efforts wasted".)

Your example works really well with in vain:

John accepted his son's choice but was really upset and felt all his efforts had been in vain.

More than one dictionary uses similar examples to illustrate in vain. Take Merriam-Webster (vain):

―in vain

1 : to no end : without success or result < her efforts were in vain>

See Oxford Learners too, “All our efforts were in vain.” The connotation is though not quite that of the Persian idiom, that one’s work was undone, but that it was unsuccessful, and hence a waste of time and effort.

A good phrase for this is all for naught.

Naught just means "nothing", so it's another way of saying all your efforts had no result.

"John accepted his son's choice but was really upset and felt his efforts were all for naught."