worst comes to worst

appetite comes with eating

Starting an activity increases one's desire to continue it.

be one's own worst enemy

To act contrary to one's own interests; to cause problems for oneself; to self-sabotage.

burn that bridge when one comes to it

To anticipate dealing with a problem or situation either by acting in a manner that alienates or cuts ties with others, or merely with the expectation of encountering trouble.

cross that bridge when one comes to it

To deal with a problem or situation only if and when it arises.

doctors make the worst patients

It is difficult to advise people on subjects that they are experts on.

in the worst way

Urgently; desperately; to an extreme degree.

one's ship comes in

One makes or comes into possession of a significant amount of money.

take something as it comes

To accept and deal with something (an event, etc.) as it occurs, with a composed state of mind.