It can be hard to feel rejected and at times we may even feel that the other person is not realizing our value and may regret missing out on us. We may alternatively that we are missing out by not being with them.
Here there are 2 concerns 1) Habit - we are addicted to the habit of calling him, messaging him, seeking his validation 2) Relationship - We may have certain faulty patterns in relationships, even other relationships, that need to be worked on.
This is completely workable, but you must dedicate yourself to therapy for this as it will take time.
Next Steps
Book a session with a psychologist and be consistent.
Health Tips
Notice what triggers you to call her message him (thoughts, time of the day, songs, other people, etc.)