confidence in myself to not be so afraid to make a wrong decision
happy, this jumped out at me. There is no "wrong" decision for you to make here. Talking to him about the pills isn't wrong. Going through his luggage isn't wrong. He's not entitled to privacy about his travel habits, not after he's cheated. Revealing your lack of trust should hurt him, not you! If he's a good person, he will take the opportunity to reassure you. If not, he'll get angry, defensive, or evasive.
Are you afraid he'll get angry at you? If he does, so what? Him being angry makes him a bad person in this situation, not you.
Are you afraid he'll leave you? That this will end your marriage? That is something you'll have to learn to make peace with. Divorce isn't the worst the thing in the world. Many people get divorced every day.
Are you afraid to be alone? Afraid that you'll be single forever? Again, not the worst thing in the world, and especially for older women, it can be a huge relief to be single.
That said, I know it can be difficult to confront someone. I hate arguments and confrontation, and I avoided both for a long time. Conflict stresses me out. Sometimes it's easier to just keep the peace, but unless the underlying problem is solved, you're just setting yourself on fire to keep everyone else warm.
