boyfriend issues (sorry this is a lot) but i need to know what other people think

i’ve been dating this guy for 3 months but known him for just about a year & we keep having arguments, disagreeing,etc. i’m not happy, he doesn’t do the things i like, he acts like he doesn’t care but claims he does. & i tell him all of this but he claims that’s it’s disrespectful to be otp with people who used to like me, or who somewhere still do & i get where he’s coming from but he knows i don’t have a lot of friends & knows i’m loyal to him. everyone ik, knows i have a boyfriend. but we just can’t get back to the relationship we used to have back when we started dating in may. or when i first met him. i don’t want to loose him but he makes me feel single. when he texts me good morning there’s no heart or anything barely even ask how my day was or how i slept. the whole thing started by him getting mad of me calling him the n word (for example n**** what ?) type of thing yk ? & i hate when he does that to me & i’ve told him that multiple times and he still does it and then the time i did it he has an issue with it, i’ve only done it roughly about 2-3 times. i don’t want to loose him but at the same time he’s older than me. he’s about to start college classes & i’m. junior in high school. no it’s not illegal before anyone says anything.