Advice on him not wanting to “settle”

I’ve been dating my bf for 3 years+ now we’re both 21 I want to get married at 24/25 but he doesn’t till 28/29. It bothers me Bc why wait a lot more years ? we’re in love & he has told me before many times he wants to marry me & that I’m the one. I already feel bad as it is to be having sex before marriage (my beliefs). Help please 🙄