You are so FORTUNATE you got the diagnosis as an adult so early!!! I envy you. I was 50 before I just happened to see an e-mail at work asking for those who knew someone with adult ADDHD or had the symptoms.
I am currently taking methyphenidate (ritalin) 54 mg time-release, celexa, and bupropion. It seems that ADDHD has several other mental conditions that come with it (e.g., bipolar disorder, depression) so be self-aware!
Here are my thoughts:
1) if you're just starting work, you don't have a "past" to overcome at your workplace (that to me is a PLUS).
2) know how your drug works during the day; my time-release is good for about eight hours; I take it with breakfast; it starts to work about 90 minutes later;
3) after eight hours if you feel distracted, take a half cup of real coffee with half a cup of milk (no need to stay awake too late)
4) maintain a good sleep hygiene/schedule
5) remember to count to ten if you feel a rush to answer or to do anything
6) keep a notepad (in code) about how you feel during the day, or just remember to review what you did, said, wrote or didn't during the day; ask how, over time, you can behave more positively
7) while drugs help, the other half of the battle is internal; join a support group or pay for group therapy; you're still young so you are more "pliable" to change your habits now rather than later
8) unless there's a miracle, you'll be on ADDHD drug(s) for the rest of your life, so plan your retirement expenses accordingly
9) do NOT abuse your drugs; do NOT let people steal your drugs; do NOT draw any suspicion or attention to yourself about these drugs; you're young and I will guess are not "wise to the world;" be careful who your friends are!
10) sign-up for google alerts on ADDHD and your drugs; it's time to self-educate yourself!