Hey deckeromega! Just thought I'd let you know that what you're experiencing is completely normal. I myself am having a possibly puberty related issue but I was right in the middle of my teenage years not too long ago (I'm technically still not out of them haha) and I experienced much the same sort of thing, where some days I'd have no drive to masturbate at all and other days I'd do it 3 or 4 times and still want to do more, only stopping because I was worried I might overwork myself. Sometimes the body releases a lot of those hormones that make you horny all at once and sometimes not at all. It's especially bad in teens and people still going through puberty because the body is being flooded with hormones and you'll find that out of all the hormones the body produces, there are only so many glands to produce them, and so certain glands produce more than one hormone. When your body goes into puberty, it ramps up hormone production, and so sometimes your body will produce a lot of extra hormones besides the ones it needs since in increasing production of one hormone, those glands will also increase production of others. It's also important to keep in mind that the human body is not a machine, it is organic. That's why it doesn't always follow through on things like clockwork. A girl doesn't usually get her period the exact same amount of days apart each month, sometimes it's early and other times late, just not by much. This means that the body can flub things like those hormones and cause odd balances where one day there's nearly none and then the next day there's a whole bunch. Also, just for your own peace of mind, remember that the teenage years (and up to age 21 for males) are just odd. Males can continue to go through puberty until age 21, so until then you may find yourself in all sorts of weird bodily situations and changes you don't quite get or understand because of it, and it might be scary. It's okay to be scared, but remember that it's nowhere near as scary for you as it would be for a guy in his 50's who has had the exact same health for 20+ years and suddenly has these issues. Sometimes, it's better to go with the flow and see what happens if what's going on isn't life-threatening.
That being said, no one on this forum is an expert (or at least they aren't unless otherwise stated haha) and so it's important to keep in mind that we can offer to reassure you and give you some insight through our own experiences, but if you really are worried, it's always best to go see a doctor and see what a medical professional has to say. If you're under 18, then your parent(s) may have to accompany you in to see the doctor, but know that if you're in a room with just the doctor and your parent(s), you're in good hands. Nothing you say will go outside of that room and there's no need to be worried. Doubly so for a psychologist.
Hope this could offer some solace to you, and hope to hear some good news from you soon. :)