Cheating

So I’ve had my share of relationships and my 2 , most serious / longest relationships , I’ve been in , I was cheated on. The first time it happened it was with my first love and it hurt me ...hard. And took my so long to get over him. The 2nd time I fell in love w someone else and he cheated on me ..): I just don’t get it. I don’t get what’s wrong w me. I’m such a chill girlfriend and down for anything and dont really think I’m unattractive. I just get so sad about it ): now I just think any guy that has interest in me is just going to hurt me...ugh any advice?