I could be a better person if I loved myself more

In my mind I keep thinking I’m a horrible and worthless person, but I think maybe that thought process is the reason I let myself down in the first place.
I could be calmer and kinder and more patient for example, if I believed for a second that I was capable of it.
I shocked myself by realising how firmly I believe that I’m not capable of being the person I would like to be. Or like, I’m not worthy of being a good or great person. I’ve been looking inside of myself and not seeing what’s already there.