It's not curable but meds help manage it. Also it's recommended to go either to therapy or some other help for learning organizational skills, if possible to learn cope with it. Since the meds only can make it easier, but doesn't take all symptoms away.

Try to get diagnosis. If you can choose, find psychiatrist or psychologist who specializes in ADHD. You'll need to do quizz or few if you get to diagnosing process. There you have to recall examples from childhood and your current life, how it affects you. You'll need the diagnosis to get prescriptions, but sounds like you truly need some help. It may take a bit time, but you will have it, even if you feel you are already in a mess... I am 26 and just got on meds. Still time to fix everything.

Sorry for the shitty money situation too. Reminds me of myself, I kept forgetting the keys and it was 20 - 50 euros each time the land lord had to open the door for me, depending if it was office hours or weekend. :x Sooo, that took like 200 euros worth off from my monthly living and as a student it was almost everything I had left after my rent!