Need advice

So I am 18 starting my senior year of high school openly gay for the most part I am shy, but could definitely improve being more social. But for the main part some days I have a man period which is a period of time, where I am just sad and want to crawl in a ball and cry. It only happens when I hear my gay friends had sex because I am a virgin and I don't know why but I get upset about it, I think I just feel left out but anyone else relate to this?