Christian and sexual sin

So I have had sex in the past and felt guilty but I had sex today with a new person since my break up and I feel like garbage. I feel so down and like I can never be forgiven. I had sex with a guy I barely know. I tried explaining That I felt guilty to the guy I had sex with and he didn't understand really and thought I was making excuses. He is a believer but doesn't have a title such as Catholic or Christian. I am not sure why I feel more guilty than in the past maybe it because I barely know him or that I thought I would only have sex with someone I love and I don't yet. I know I definitely feel guilty because this is the third person I have slept with. but any Christians have advice or stories like mine?