Who do i choose? either the ex or the other guy?

me and mi ex was together for 11 months. and we had broken up a few times b4. but we always got back together, he was mi bestfriend and i wanna spend mi whole life with him. but we broke up bout a month ago and 5 days after we broke up he got with his ex. but while they were datin he told me one nite that he still loved me and that he wanted to be with me. but now im talkin to this one guy and he was mi ex's bestfriend. and mi ex has called me alot of nasty words since we broke up. he has said that he regrets everything with me and all kinds of stuff. but this other guy is really sweet and knows what to say to make me smile. but im not in love with him. im still in love with my ex, however. now my ex is talking bout getting back togehther. but im scared that he is just gonna leave me again.... and im scared to hurt this other guy cuz he was one of mi close friends b4 me and mi ex broke up.... any advice? plz help me :(