AM I COMPLETELY ON MY OWN?

Like everyone, I have the same worries about the environment and the types of people I will meet, the professors, the workload, the consequences, the adjustment, and the transition onto college, yet one of my most profound worries are if I will be completely on my own. I mean, I know we have to be independent and responsible for ourselves, but does that mean no one will help you in a time of need? For example, I'm one of those students where if I don't understand something I will be in the teachers' way until I feel confident that I fully comprehend what I once didn't understand. My worry is, will the professors be willing to help us after class or before, if we don't understand a topic? I feel like the media and world has portrayed professors to be the "big bad bullies" or " strict sally's" but I want to believe that they are not all like that. Plus, I'm worried that if I am in a class with at least a hundred students, how will the professor help me? Or do we have to seek help from other students? Are there tutors? Believe it or not, these are my most major stress factors, since I overthink a lot, or even if I have the slightest most obvious issue in any mathematical problem or subject, I need to know how, why, and what can I do to fix it. So my question is, are professors willing to help out a student if they don't understand something, before or after class, or are they tired and do they want to leave as soon as possible, therefore leaving us to turn to peers for help?