Originally Answered: How can I stop feeling insecure about.?
I can relate to how you're feeling. I was never insecure before I was cheated on, and since then, I'm having a really hard time dealing with it, but I think it's only natural. It's in every biological being to protect yourself from pain, is it not? And it's not just physical, but emotional pain, too (at least for humans).
Not to mention, it sucks being screwed over.
But, we're all flawed, nonetheless, and one man's downfall may not necessarily be the same for the next. While you've been hurt twice and are having a hard time, the best thing would be to talk about it. Let the guy know how you feel, let him understand where you're coming from. And if you were giving him a real chance, a lot of these insecurities need to disappear. Maybe write about it? Talk to a friend who can relate? It's unfair for him to have to suffer the baggage you've kept from other relationships, even though you're hiding it from him, it will surface somehow. I mean, if you're always so insecure about him, he won't be able to REALLY reach you emotionally and mentally, and trust me, he'll notice after a while.
But don't let your insecurities start bringing your relationship down, e.g. checking his phone, constantly questioning him about where he's been, what time did he get home, etc etc. I know you haven't done that yet, as you stated, but if you let your insecurities grow, it will start making you controlling and possessive and it'll kill your relationship. So, open up to the guy and let him know where you're coming from. If he's worth it, he'll talk things out with you and actually understand how you feel. Not every guy is the same, trust me.