I have had similar challenges my entire professional life. I am well educated (undergraduate business degree from a top-ranked university, graduated from law school magna cum laude, obtained CPA designation), intelligent, and hard working. I have had a lifetime of failed business and work efforts. Here’s what I did:
– Acceptance. While it seems at the time you are making the best decisions, life has taught you that your decision making ability is faulty. You need to accept that this is a challenging area for you and that it is a result of biology that is outside your control. You also need to find a way (therapy, medication, acceptance) to let go of the shame. Remember, ADHD is, among other things, a defect in your executive function.
– Manage your symptoms and behaviors – Ask for help. I have learned to ask others for help. Whether is asking others for their opinions regarding choices I want to make or asking questions about plans that I may have, etc. For various reasons, asking for help is hard for me, but I know it is a necessary form of management of my ADHD symptoms. Best of luck.