Is my boyfriend justified for being possessive?

Ok so i have been seeing him for 2 and half months now. From the first day, he wanted me to cut all ties to all other men in my life apart from my family including my best friend. I used to be a serial DATER in the past and have a few guys who call me now and then. Though I might have been frisky with one of them in the past before I met my boyfriend, the relationships with the other guys are all purely platonic now. My boyfriend asks me who is calling everytime my phone rings and when I refuse to answer the call, he demands to know who is calling. He accuses me of sleeping with the past guys when we fight and when I broke up with him once. He wants me to hang out with him all the time and gets mad if i don;t answer the phone the first time he calls. He started talking bull about wanting to marry me even after the first week. I am not even considering that, though I am 26, I don't think he's the one for me at least i don't know yet. he's even said the L- word! I know I don't love him, but the truth is I care about him and have never cheated. Once I find a guy I want to date seriously, I usually don't keep seeing the other guys. But the more my bf keeps accusing me and fighting me, the more I go back and keep in touch with the other guys. Even though i am not dating them, I still want them around because it seems that my boyfriend and I won't be together long and i don't wanna cut them out of my life completely just incase.... Plus there's this other guy who seems to like me very much now and just maybe? I am so confused. My Bf says He doesn't want to leave me but I am not so sure if I want to stay...So what do y'all think? Is he right to be possessive and jealous?