I feel like I can definitely relate. I had the same problem with customer service jobs . Don’t think that customer service jobs are easy there are plenty of people who are very smart but are not suited to that sort of work for various reasons.It sounds like you would be better maybe doing work where you can work on one task really intently or set your own pace maybe freelance work? It also sounds like you have anxiety that is possibly related to your add but could be separate.Just remember you are not stupid and I am sure you have things you are great at. I am very good at music and not my normal day to day job so I channel my energy into that, that helps me even though I am not great at my day to day work. It is not an easy road having add ,adhd but you will be ok. Taking medication helps for me but is not the be all and end all.