does jacking off change the amount of times you get hard? like if you masturbate often, would you get hard more often or less, or does it even make a difference
It could make a difference. You might notice after wanking your next errection won't be as stiff.
For a time after ejaculation most guys find they are not aroused as easily, so I expect if you masturbate very often the number of times you get hard apart from the masturbation would be smaller.