Advice about dating and living together

Hi guys! I’ve been a Christian my whole life, however, I have had some ups and downs over the years. I’m 21F and my boyfriend is 26M, we have been dating for almost two years now and we live together. We originally started living together because the place I was living was not good for me and he was the best option for me. Flash forward to now, we have moved across country together and I’ve been struggling with my faith! We had been “doing the do”, but I feel so guilty, and I wanted to stop and wait for marriage. He is perfectly okay with it, but now, I just still feel guilty.. I feel like if I’m going to continue to live with him we should be married, but he thinks I’m too young, and maybe he is right, but I know I want him forever in my life and I never had any intention of sleeping with more than one man. I feel like we should just get married, but I don’t know guys! Its stressing me 😭