Resist the trick of Shaytan where he keeps reminding you of your sins and bad past in order to render you useless and hopeless!
No by Allah our Lord is at-Tawwab, al-Ghafoor, al-Afuww’!
Let no one, not even your own nafs, your kith & kin, your friends or foes tell you otherwise! A sin that has been repented from is like one that was never committed. So stop this waswaas of shaytan and get on with the great task of re-building the Ummah!
But always keep in mind the three conditions of repentance:
1- You should give up the sin
2- You should regret having done it
3- You should resolve never to go back to it.
Once this is done sincerely, move on and do not seek to challenge the Mercy of the Ever-Merciful One! Rather, be grateful and be vigilant. Indeed, He is closer to His slave than his jugular vein!