Hello,
If you've had 70 interviews clearly you have a good CV. You probably don't get chosen because you may not be at your best during interviews. You should watch videos, look online for advice and practise with other people or yourself. Learn to answer common interview questions like 'why do you want to work here?', 'give me a time when you had to work to a strict deadline?' or 'Give me your produest achievement'. Use the STAR technique when appropriate and make sure your answers are coherent because it is not enough that you have the technical skills, companies also want to see if you are a fit personality-wise as well.
Also, if they ask questions such as 'why you haven't worked since 2017', just say that you wanted to focus on university to get the best grade possible. Also I recommend you do not tell them about drugs or your mental health (unless you have criminal record), because although yes you should be honest, at the end of the day they may not hire you because they think you are not a fit. Because no matter how 'nice' the hiring person might be, they will probably have an unconscious bias not to hire you after hearing of your problems.