Everything perfect but still want to break up?

Hi i'm a 17yr old (18 this year) female and my boyfriend is 22 yrs old i consciously waited until after i graduated high school 2 have a bf even though i got offers from guys to be with them in a relationship, so my bf is my first bf and i'm his first gf, we had our first kiss together, and we are both virgins,and we are both only children ,we've been together 6 months now and it seems like the "perfect" relationship but i still want 2 break up, my best friend says i'm crazy 2 want 2 break up with him since we are both sharing firsts but i don't feel like i only want 2 be with 1 guy my whole life i don't mean that i want 2 go sleeping around with everybody but i just want 2 date around and see whats out there before i settle down with this 1 guy, is that wrong?is it normal for me to want to do that?or is it mean to him? because he says he wants to get married to me and that he is willing to wait until i finish my studies to do so and he gets upset want i hint that marriage may be 1 of the last things on my mind, i mean there are so many things i want 2 do marriage and kids seem like obstacles, things that would slow me down, he already said he loved me 3 1/2 months into the realationship and thats big 4 him since he has never said that 2 anyone not even his mother, he doesn't express his feelings in words, more in actions,it is a big thing for me too since i've never said that 2 anyone either. He is really serious about this relationship but i believe i'm not as into it as he is and i know he is serious because he has already introduced me to his parents(he insisted i meet his mother) which was not only a big thing for the fact that its his parents but also because he is of a different race (i'm African and he's Indian,we're both from the Caribbean) but his parents really like me, his mother even invited me to some yoga thing i didn't go to and a beach house that i did go to where he introduced me to their friends and friends of the family, on the way back i asked him why were his parents so intent on me meeting their friends (i wanted 2 stay in the car and wait on him but his mother insisted i come in) and he jokingly said that they saw me as their daughter in law, but i think he was serious, this relationship is getting too serious to fast, should i break up with him? is it wrong for me to want 2 date around first before settling down? or is it ridiculous to date around when he seems like the perfect guy to marry?, he is caring, kind, ambitious,he bought his own car, he has a great job in a big company, he just finished some studies in electrical engineering and plans to continue and his father and him started their own business a few years ago, i'm really confused cause my best friend says that its pointless dating around because all u will have is a string of meaningless ual partners that would not make u feel good about yourself, thats why i'm hesitant to break up with him and end up with someone worse because there was a guy that really liked me and wanted to be with me while i was with my bf but i didn't break up with my bf for him and now i felt like i made the right decision,i'm really confused,because on top of all that my bf is not what i'm typically attracted to, i like boys with long hair and tattoos and piercings who like death metal music even though i'm not into those kinda stuff,i feel like if this relationship is getting too serious too fast can somebody help me?