Op- I won’t pile on, but I will give you a homework assignment to do over the break.
Why on earth would you be interviewing for roles in investment banking? I cannot think of a worse career path for someone with a diagnosed anxiety disorder, who also seems to have trouble with organization/preparation/sticking to a time table.
Do you know anyone in IBanking? The hours are long, the deadlines are brutal and the consequences for missing them are extreme. Preparation- things like working out a piece of analysis six different ways with different assumptions because you don’t know which scenario the MD wants to present- is key. Working endlessly to be prepared for a meeting even if you only have a 15 second piece to present- but that 15 seconds might take you a week to prep for.
None of this sounds like you to be honest. There are dozens of careers where your smarts and creativity and analytical skills will propel you, that will not drive you and everyone in your life insane.
Think about why on earth you want to interview with I banks! Your long post reveals a LOT about you and your attitudes and strengths and weaknesses, and does NOT scream “future banker” to me. You think the professor has been unhelpful with your explanations? Try explaining to an MD why you got lost getting to a meeting, or why you were late, or why you missed/skipped several sessions (note to yourself from here on out for the rest of your life- anything marked optional is actually required if you want to do well) or why you want leniency on an already lenient policy about missing a class.