How do you change your personality?

I'm 22 years old and I let my feelings run my life. The constant fear of being judged is always on my mind. I've never been able to get comfortable around people in groups. I always feel like everyone arouund me is better than me. I don't know how to stay positive and not be awkward its like I'm naturally weird and awkward. I don't know how to love myself I'm such a weak person. I don't feel like a man at all. I see people I know and they look confident and comfortale in their own skin. They could be faking it but they do it so well and at least they can I don't know how to fake it I want it to be real! I still feel like that awkeward teenager Its like I'm scared of life someone can put their hand near me and I've caught myself flinching wtf? I just want to be happy I deserve to be happy! This has been going on long enough i NEED to take control of my thoughts and make decisions to stop being lazy and worried but how do I start?