Due to this line, it'll lead you to believe that they're talking about a significant other. With the s/o, they felt safe, secure, and loved, like they were their home. Without the person, they feel lost and alone in life, along with hopeless.
Past promises have been broken and they want them to be mended, Burning the candle at both ends is an idiom which means to exhaust yourself. The 'candle'(themself) has seemed to 'burn out' so they can no longer find their way home or to where they feel safe and comfortable, but they don't even remeber where that is anymore due to the extreme amount of changes. They've finally gotten to the point where they realize what's going on.
They've been attempting to regain their past or have been living in their past for so long that they're not aware of the life in front of them and what's going on in it. Everything that happens to the person, it brings back old memories that are hard to forget, regardless of how hard they want them to go away or come to terms with them.