reheatedmacandcheese28
If you're so sure that he will not cheat on you, then try not to be so stressed about the possibility of it actually happening.
You're contradicting yourself, you just have to trust him.
Trust, Love, &Live.
That's exactly what this post is about. She KNOWS he won't cheat on her and she KNOWS that she doesn't need to be so stressed out. The problem is HOW. So on to my advice..
First of all, if you haven't already, let him know that he isn't the problem, it's your own insecurities; though it sounds that he already knows that. You need to have a life of your own apart from your relationship. Get a hobby like swimming or running, maybe join a sport or an after school program, or even get a job. Making yourself more busy should give you less time to worry over it.
Make a list of your strengths and weaknesses. Use the strengths to reassure yourself and think of solutions on how to turn your weaknesses into strengths. The more you accomplish on your own, the more secure you'll feel about yourself and ultimately discover why he chose you- because you're an amazing girl who stands out like no other.
I hope that helps. Good luck!