Girls help me!guys 2 if you care!?

I been with my BF for 4 yrs and i love him but he has been pressuring me to have . iwant to save it for marriage. we got engaged a yr ago then he took the ring back cause I wont have with him. he will not marry me and no whe is cheating on me & wants it over. SHOULD I HAVE WITH HIM-WILL THAT MAKE HIM STAY AND BE FAITHFUL 2 ME? OR Will he use me & dump me. I love him but I dont want to give up my virginity & nothing and be used and tossed & more hurt. What should I do? what will he do if i do it with him? he mistreats me now doesnt spend any time with me, calls me a ***** now & then- & when we are intimate but havent gone all the way-he doesnt want to see me after that! thats why I hold back cause how makes me feel after we get sort of close. im scared if i go all the way he will leave me. Are my fears warranted?