ANSWER:
This is a very critical stage you are going through! This is the fork of the road where Satan is doing his level best for you not to pass this stage! This is why he gets you depressed, sad and lonely! He reminds you of your previous sins and makes you miss them and desire them. You must remain steadfast, make a lot of Duaa to Allah to help you and avoid anything that reminds you of old sins. You must occupy yourself and time with beneficial things and surround yourself with practicing righteous Muslims 24/7, and in few weeks time, you will get over such negative thoughts and feelings in Sha Allah.