Use this phrase when you're telling a story. It's useful to tell a story about this kind of situation:

1. You had a problem.
2. You tried a few different ways to solve it which didn't work.
3. You use "I finally had to ___" to express the last thing that you tried.

In the example above, the speaker tried to get money in a few other ways. Asking his parents was the last thing that he tried.

Here's another example:

I finally had to just cut him off.