I have been in your shoes and have felt and can agree with your concerns. I don't think you're overreacting, but I think the answer will differ according to people's personalities and their own experiences in life--which are not exactly like yours.
I would focus on YOU. On you being emotionally secure and happy. I'm not sure about trusting him completely, we're human, we make mistakes. I would trust in God. I would focus on bettering myself... going after a quiet peace in your heart that keeps you grounded... focused on smiling, laughing, looking at the positives, praying, having goals and dreams and Living YOUR life NOW... You go out and laugh with your girlfriends too. Work on not being co-dependent... not having to worry where he's at or what he's doing... not because he's trustworthy, but because you need your mental and emotional health to be the best woman you can be. And being tied up in changing someone else is an obstacle.
People need to be FREE. Free to be who they want to be. It's the only way they'll change. You share your feelings and what you think once... and then let him decide as he wishes because only he can decide what he wants. And you don't want to be the cause of any resentfulness on his part. No matter what you say, he will still go... no one likes to be told what to do or not to do, etc. But sharing your feelings is fine... ONCE. If you keep on talking about it, you resort to nagging... which is annoying and pushes him away.
But you also need boundaries. You should know what you would do if you ever find out he cheats on you, etc. Maintain your self-respect... you have options of 'separating, if not divorcing', working things out through counseling, there are groups, etc. You are a strong woman, who will live her life, better herself, speak what you think once, accept him as he is... BUT cheating is not okay, ever. And you shouldn't have to act as if nothing happened... you also need healing... you either forgive, work through it, separate, divorce... but do something that maintains your self-respect. It's okay to forgive... it's also okay to 'separate' when needed.
Secure Woman... who loves, laughs, and lives. You can only choose for yourself and change yourself... for the rest, you can only speak up once respectfully, and pray
and let them be who they want to be... but don't be a doormat when hurt... be strong and take your time to heal.