How can I get all my sins forgiven without going on hajj
Perform salah-at Tawba it is a
Tahajjud prayer which is to be done after isha and before fajr.
There is a complete different between seeking forgiveness and repenting.
When perform tawba you have to truthfully and whole heartedly feel bad for your sin promise never to do it again and truly mean it. Of course seeking forgiveness is important but it’s more heartfelt when truly apologetic about it and Allah SWT knows what’s in your heart.
https://islamqa.org/shafii/qibla-shafii/33940 read this and I also suggest you watch this video
Recite Astaghfirullah constantly. Say it 3 times after every salat and minimum of 100 times a day. It means, "I seek forgiveness from Allah". Allah's Messenger (ﷺ) said, "Whoever says, 'Subhan Allah wa bihamdihi,' 100 times a day, will be forgiven all his sins even if they were as much as the foam of the sea.