Sounds like a cop-out, but one of the reasons you don't need to be in a relationship is because you have too much on your plate.
Any relationship requires time, energy, and a level of devotion to function properly.
If you're currently holding down two jobs, in school part-time, acting as a live-in babysitter to your younger siblings, and barely holding on to a social life, a relationship is not what you need right now.
Sure, the idea of "if you really want to make something work, you can make it work" SOUNDS good, but if you're really honest with yourself, you will see how unrealistic that idea is.
Entering into a relationship when you're already busy with a million other things will only lead to destruction for you and your new mate.