HOW TO KEEP A MAN WHILE STAYING ABSTINENCE

I’m 20 years old and I’ve never been in a serious or long relationship. Does anyone have any tips for starting transitioning into a serious relationship? I believe it’s something I’m missing. I’ve dated a guy 3 months and we never kissed or had sex. I’m a virgin btw. All of a sudden one day he told me he found someone else. I don’t want this to happen again. Any advice on keeping a man while waiting until marriage to have sex.