Have you thought about setting up a schedule for yourself?
My interests are currently physical skills/exercises and I've found scheduling them has really helped me to be less impulsive, more committed, and to settle into a routine. Some days I might not feel like it, but I do it anyway but just ease off the intensity and duration. If I know I'm going to be doing such and such on some day then I find myself looking forward to it, rather than just going out and doing it (without being prepared and getting frustrated at failure).