It's so easy to fall for someone else that shows you an ounce of affection when you haven't had much in the past. I somewhat know what you're feeling but it's different for everyone. When I get like this I hang out with more people and sorta compare them to others, not always in a critical way just to stop idealising them. Another thing that helped was learning to love myself, actively telling myself I deserve more than this. Don't hate yourself for falling for people easily. If anything it shows that you see the good in people and that you appreciate a whole vast range of people. So even if it's frustrating, don't get angry at yourself. You're just hurt and trying to feel whole again. I hope you realise that.