Congratulations on 16 days sober...that's great!. I also felt like this when i first quit drinking and everything was very raw. With time i managed to let go of feeling regretful about things in the past that i cant change. I ruined many events and special times with being drunk but i cant do anything about that now. I work on making amends for those times by being sober today. Keep moving forward and focusing on the future and your recovery. Think of all the great sober times you can have with friends now. You can make great new memories. Its never too late to make positive changes.