university concerns

i had always hoped to get into college when i was younger. hell i even gotten encouraged too many times to count. now i've made it into a university and everyone just telling me negative things. (financial debt, frat boys, parties, roommate horror stories) i am literally so afraid now. i have struggled with certain mental illnesses as early as i could remember (clinical depression, clinical anxiety, OCD, ADHD unmedicated because of certain circumstances) most of the time, i act and look like the average person. what goes on inside is SOOOO much different though. i mask my whole personality pretty much every day and senior year has been such a fucking nightmare. i'm hoping to get a room by myself without paying extra for my stupid baby issues. i am also afraid of debt, my family tells me everything will be okay and they will take care of it. my sister on the other hand (20yrs) has been rather discouraging about everything, acting like i'm a financial burden (she's in community college and turned that 2 year into 4 years from failing classes). on top of that i KNOWWW y'all have seen that story of the girl who secretly poisoned her roommate; in which that is actually terrifying. i'm hoping anyone in this world has anything good to say about college other than the possible nightmares i have previously mentioned. i'm scared to be a real adult even though i'm already 18. am i ridiculous and silly and insane or am i okay to have these intense fears guys pls help