On the internet it says:
1. Share your feelings
Instead of insults, ultimatums, prohibitions and other manipulations, just talk and listen to each other. Learn to trust! Be sincere and respectful to your partner and stay calm so as not to quarrel or jump to conclusions.

2. Look for a compromise

Try to discuss painful moments and find a compromise so as not to warm up, but to calm the feeling of jealousy. Agree on what is acceptable and what is not in your couple, and make sure to come to a mutual agreement.

3. Build trust
Love suffocates in a relationship that lacks trust. Even in close relationships, each partner has the right to personal boundaries and personal time. Trust and freedom are the keys to strong and lasting relationships.

4. Less fantasy
Stop mixing imagination with reality and look at everything in black and white. Trust that all is well in your relationship and take your mind off your doubts with enjoyable and rewarding activities, whether it's work, watching movies, walking, or exercising.

I hope my blog is useful to at least someone and helps to save someone's relationship!