How can light therapy help me in regulating my sleep schedule?

Yes. Yes if you have sadd. This is useful for people who live far enough away from the equator to have very long, dark winters. They become depressed in winter.
It can adjust. Our tendency to feel sleepy at certain times and awake other times are strongly influenced by natural body rhythms called the sleep wake circadian rhythm. This sleep and wake cycle is strongly affected by the light that enters our eyes. Carefully timed light therapy allows physicians to adjust an individuals rhythm so that they feel more awake and alert. Would recommend seeing a specialist.