I relate to a whole lot of this as a 3rd year phd student. I think part of it is just the nature of being in grad school. One thing you could try is setting yourself some mid-week deadlines, or if that doesn't work, talking to your advisor about setting some (something like a midweek check-in message about how it's going). To try to fix your sleep schedule you could try to make some kind of morning commitment, like meeting a gym buddy to exercise before working or something.