I do metta practice after every sitting session and it was one of my first lessons regarding what true caring and kindness are about. I grew up in a very abusive home and for my first 30 years I didn't not know what caring wise kindness was. I learned, firstly metta is a balm for a sore heart, I also see it as protection for my mind as well, it's like a shield for me. One of my favorite practices, but difficult, many times I don't get a warm happy feeling or bliss. Sometimes it's really difficult to give myself metta, let alone anyone else. I need a calm and steady mind to see this, I was told if it is too difficult to give metta to some really horrible person, like someone who has abused me I can do this later when I am more mature in my practice. I took that advice, I can now clearly see the people in my minds eye who have been hurtful to others and to me while staying calm and (aware). But that has taken me many years to do.
I hope this advice helps @purpleplanet. One step at a time
Form is like a glob of foam; feeling, a bubble; perception, a mirage; fabrications, a banana tree; consciousness, a magic trick this has been taught by the Kinsman of the Sun. Phena Sutta: Foam