@Discombobulated hit the nail in the head.

One important part in the practise of Mindfulness is accept and let yourself having these feelings. Knowing that it’s normal and understandable you feel it that way.
It’s all about not fighting or feeling bad for them because this is when they may grow.

It takes time to get over a loss.
Mindfulness helps you to cope with this feelings and the thoughts that produce the former.

There’s a part of Mindfulness called Mindfulness of compassion and if I’m not wrong, there are in the net audios about the people who developed.
I got to forgive people’s behaviours from my past who unluckily weren’t present anymore.

I think I wrote a thread about Mindfulness. I’m gonna look it up. Just in case, you might be interested.
Mindfulness is a technique introduced now in many therapies.

About Mindfulness