Lead.
Good Jealousy vs. Bad Jealousy
Give love with free benefits
Call Your Jealousy What It Really Is: Fear
Identify the source of your fear
Identify Triggers/and discuss honestly
Consider Why Your Partner Deserves Trust, and What You Stand To Lose if You Don't Give It
Respect Your Partner's Right To Privacy
Encourage Your Partner's Independence, Don't Thwart It
Accept That You Have No Control Over Another Person's Actions
Accept That You Have No Control Over Other People
At the end of the day, if you give trust and are proven wrong, you can take comfort in the fact that you still did everything right. You can walk away from the relationship, head held high because you gave someone an opportunity to be loved and trusted, and they squandered it. That's on them, not you.
However, having the relationship deteriorate due to your inability to overcome your jealousy, because you never gave them the opportunity to be trusted in first place—that rests squarely on you. She will now be the one you let get away, or rather, forced to leave due to your antics. In the end, it's really your choice: Which feelings would you rather be left with?