It sounds like you're referencing a phrase often used in emotional or heartfelt contexts, like in songs or poetry. The phrase "just when I needed you most" is commonly about feeling support or presence right at a crucial time. Are you looking for a song, poem, or a completion of this phrase? For example, "Just When I Needed You Most" is also a famous song by Randy VanWarmer. Let me know how you'd like me to help!