If God forgives all sins, why can’t I forgive myself?

I have committed many sins. Sins that make me feel disgust and regret when I think about them. I feel like I deserve Hell. I don’t want to go to Hell. I have tried to live better, be better. I have been tempted to fall back into those old sins but I haven’t. I have tried to truly move on. I fall short in other ways but my darker sins, the sins that make me hate my reflection someday, I have moved on from and never committed again. I’m not perfect but I have long accepted God into my heart. I pray regularly and even though I’m non orthodox, I still praise God in my own way. Yet even though I know that God forgives all sins and Jesus died for my sins, in my heart I cannot forgive myself nor can I fathom anyone forgiving me. I know God is merciful and forgiving, I know that so long as I accept God and Jesus Christ, I will be forgiven. So why can’t I make peace with myself and forgive me?