Why Do I Not Wanna?

what is it that causes me to not want to do things - to make me believe they’re too much effort? i mean, obviously i understand the situational cause, but there’s got to be some sort of scientific explanation, too, right? like my brain isn’t producing enough [insert latin chemical name here] and this is what causes me to be unable to do (what should be) simple things like do the laundry or call the doctor’s office. i need to be enlightened because if there’s something i can do to offset this symptom, i need to be doing it. i don’t do much anyway, what with the being poor and living far from people and not having a lot of going-out-with friends; i need to keep from being completely inert. my life cannot become only work and sitting on my couch browsing the interwebs and crying, because that’s certainly not going to help my mental state. any science-minded people have any answers?