Stop Header Overflow

On the left page header of my 30-day devotional, I'm including the day and day's title in the header. Two of the chapter titles are a bit long. How can I avoid the chapter from overflowing? For example, this is what the chapter heading looks like:

Day 16:

Steven's Saga (Part 1)

And Jesus Stood Up

To make sure that only the first two lines are showing up in the TOC, I used the forced line break to separate the first and second lines and the Paragraph Return from the Type menu to separate lines 2 from three. It worked perfectly for the TOC but not for the pages following this devotion. How can I fix the master page to only reflect the first two lines?