confused

Well i have been with my partner for 4 an half years and about a month ago he told me he didnt love me no more and he wanted to break up  but typical girl i begged him back that i will change and i thought it was all my fault but it was nothing till do with me but from that has happend i cant trust him cause i dunno when he is gunna say it again its just to much stress to handle cause im only 18 im not happy anymore and im crying everyday and i told him i need a break from it all but its just so difficult cause ive started talking to this other bloke and i really like him its just soo confusing and i would appriciate any help wot so ever cause i just feel like im gunna explode with all this stress.