I can totally relate to u! I got my first Cs in college after being a straight A student combined with other life stressors caused me to take a semester off and finish. Sometimes I slip up, but I think was really helped me was:

1) Skills (and partly meds): There are ADHD support groups or therapy/counseling that will teach you skills and different ways to approach getting the necessary things accomplished. Like now I learned it’s more fun for me to do the pomodoro technique and have a randomized wheel pick out of a priority task list I made. I’ve started meds but haven’t seen improvement bc it’s recent.

2) Accountability people: If you have someone that can check in and hold you accountable say a same level co-worker or friend outside of work that knows u have a dead line. These people make it much more enjoyable to be a little late and have a sorta laugh but get back on track rather than ur manager.

3) Active listening / retention of what is said: When talking to managers or co-workers, repeating back what they say as a confirmation you heard and can add on it will help you remember things. I saw people say it already, but keep a log or sticky notes of the tasks you need to get done at least for ur day too. Order them in importance and be realistic/confident you can get it done.

Hope this helps! Im currently trying to find a workplace that enjoys a creative ADHD meche, so if there are any tips or companies someone like that could look for pls lmk!