How does one repent and remain steadfast on the straight path?

If one has repented and wants to be become a more practising Muslim but points below get in the way, how do they deal with them from an Islamic prospective? - If one is prevented from praying while at work. - Keeps on remembering sins committed in the past and feeling guilty because of them. - Surrounded by a bad environment related to their life and habits before repenting. Feeling lonely with no one to care for and support.