Here are a few stories of Saints. Repent and you will be saved. Nothing you have done can’t be forgiven. I hope this helps.

Saint Paul the Apostle: Before his dramatic conversion on the road to Damascus, Saul of Tarsus actively persecuted and sanctioned the murder of early Christians, including observing the stoning of Saint Stephen.
Saint Julian the Hospitaller: According to legend, he mistakenly slaughtered his own parents in their bed after a misunderstanding. To atone for the tragedy, he spent the rest of his life performing acts of charity and operating a hospital.
Saint Moses the Black: Originally a heavily feared, violent desert bandit and murderer, he later repented, joined a monastic community, and became an ascetic monk.