I'm kinda confused of what's really love, what's falling in love?

I mean I used to be so infatuated with one guy for two years and he wasn't even my boyfriend but now, this week I think I'm in love with this guy then next week I think I'm in love with another guy then next week, another guy in the picture again...I mean am I just lonely that's why I think I'm in love with these guys? coz it's been 4 years since I had a boyfriend.