How do I manage? with the help of assistive tools. Calendars, timers, reminders, alarms. They all contribute to the ability to get something done. You also need to learn techniques to help control the emotions that are involved with the procrastination you face. The good news is you can improve. The bad news is, if you have ADHD, you'll probably never be at the same level of someone who doesn't suffer from it.

My comment history offers other advice and suggestions for ADHD. It's a long struggle but it's worth it.