When you do not trust your partner you make it harder for him to do the right thing, but when you trust him he will does his best to maintain that trust. When you do not trust your partner he is more likely to cheat because he will feels regardless if he cheat or not you will always doubt him so what is the point.
The atmosphere is not welcoming; as a result your partner barely wants to come home because of unnecessary stress you created. The partner might even walk away from the relationship for lack of confidence in him because you seem to questioning everything he does or says.
I cannot speak for all, but I know it is normal to be jealous to some level because that shows your partner you care, but over does it can damage the relationship.
How to overcome jealousy? Simply, start trusting more even if your best friend tells you things that could be true. Show him you trust him, and stop questioning everything he says or does.
Believe it or not, you have the key to cause your partner to always want to do the right thing, where he would rather die than to hurt you in anyway.
Le me hear from you,
Marie L. M.