I have experienced this, and I will share my opinions.
After breaking up with the person you care about, it's normal to still miss and want him to return. But there is a reason why all this happened. Humans grow and change, things also change, and sometimes we can only accept those changes. One day, you will also wake up with that feeling of peace, because eventually your heart will be able to accept everything and finally can release the things that you must release.

Thanks for this My Teacher @nomad-magus