I am reaching a breaking point

Hi:

I have had a history of holding onto the past and to a lot of anger, bitterness, and hurt towards other people who have hurt me or mistreated me in some way. I have even lashed out at some of those people while not even realizing why I was really angry and hurt with them. Therefore, I am learning not only to write fake letters and do mindfulness but that it's ok to let these people know how I feel without calling them ugly names.

For example, I had been holding a grudge at some former toxic friends who mother and daughter because they they didn't treat me right even though I cut them off. Well, I then realize that I was upset because they were not very supportive of me when my aunt died. The daughter, said some pretty nasty things about me to a friend that same year as well that were incredibly hurtful. Therefore, I felt like wanting to last out but I talked to my therapist instead and then worked through it. Then afterwards, I realized that I felt betrayed by these people because they weren't being supportive. So I wrote a tactful email yesterday explaining to them how I felt and it helped.