I wonder how much people can ask of me before I should start questioning if I'm being slightly exploited?

I mean, I'm generally a pretty helpful person, and I try to help most of my friends when I know they need help. And I offer help a lot too, like you'd hardly find me saying no to anyone unless I didn't like the person. I mean, I'd go to school 2 hours early in the morning just to help a friend prepare for her test, imagine what I'd do for my crush. I'm super glad that my crush is coming to me, but recently I was asked to help in a big project (it's big for my crush but would probably just take me a few hours) and it triggered the worry that my crush only saw me as a super helpful smart friend, and led to thoughts about getting exploited because people had mentioned that I needed to learn to say no more.

My crush would never exploit me duh ahah I wouldn't have a crush on my crush if that could even be a potential situation, but some of my acquaintances might ahaha and maybe even teachers idk hahha. I genuinely can't tell sometimes though, if people are asking too much of me. sighz.