For me personally, I had tons of anger growing up. I never really realized until age 16 that my life with a shit fest from my parent's divorce to my father going to jail and walking out on my mom to raise 5 kids on her own with no job or degree. I was able to convince my mom to start me in therapy and honestly, it was one of the best decisions I ever made. I had attempted suicide 3 times and was extremely depressed and hated myself. I don't know how much you can relate to my story but here's what therapy taught me.
I was not alone, that was the biggest thing to me, I was not crazy, insane, and so many people around me including my siblings have gone through what I have. In therapy, it can be just like talking to a friend about all the terrible things in your life but it's a complete stranger who's entire life would be ruined if they dared share any details about what you tell them. Some of the most trustworthy people (unless you did something illegal and have not been prosecuted for it) BTW I am speaking from my experiences in the USA. So maybe research into what the laws are in your country if different.
But the thing about therapists is they start out a stranger and they kinda turn into a friend in a professional way I guess. They can give you advice on how to cope with issues and approach hard things in your life in a safe way. It's nice to have a professional tell you that what you are going through isn't abnormal most of the time. Many people hide their issues I feel more so in the male gender. I never knew there were people like me when I was growing up and it got to the point that I tried killing myself multiple times. My life is better now and it's not perfect, everyone has their shit, but through years of therapy and medication I live a mostly normal life and I stand a large advocate for going to therapy. My friend once told me that even mentally stable people should try going to therapy every 6 months like going to the dentist if they can afford to. Cause we all got shit to deal with, and sometimes you don't realize all the stuff you have been suppressing and not addressing.