I am struggling due to insufficient background in a graduate course and feel like a moron. What do I do? I just started an Astronomy PhD program, which due to COVID has been all-online so far. Research and my computational methods course have been going OK, but I'm being utterly destroyed by my Galactic Dynamics course. It's clear to me that I didn't have the necessary mathematical physics background going in, so I've spent all semester struggling. It's reached the point that I spend more time on the problem sets on this course than on my research and other class combined, and I can still barely do it. I've been working on nothing but the current problem set since Tuesday, without making any significant progress. I've been reaching out to the professor for questions via Slack, but as often as not this leaves me more confused than when I started. I'm starting to doubt my ability to do this, but I can't quit. What do I do?
Sounds like my Physics II course decades back.  The effort on that course was greater than the effort on all other courses combined.  Little did I know that I took it from Paul Chu, who at the time was a Physics Superstar, and he wasn't going to &quot;just pass anyone&quot;.
Somehow I managed to get a B.  To me that B was worth more than all the A's I obtained combined.
Hard material is not a sign of you being a moron.  Perhaps you're not ready for the course; but, the entire idea of taking a course is to challenge you with new material.  The harder the challenge, the more you will learn.
Take it easy on yourself.  Try to do as much as possible without over involving your professor, but do use an hour of their &quot;office hours&quot; to go over problems you have difficulty with.  Be very well prepared for this hour, showing them what approaches you've tried and failed at, and can they teach you &quot;how to approach the problem&quot; instead of &quot;how to do the work&quot;.
For support, find others in your class that seem to be bright enough to warrant working with, and form a study group.  If the group starts to look like an unbalanced &quot;share the answers&quot; group, get out of it, as it will do nothing to prepare you for the exams.
Rearrange your schedule for the reality that you'll be spending six to eight hours a day doing this class's work, until you can gain enough mastery to cut it down to a mere four hours a day.  Remember, it won't last forever, you only need to keep up the crazy schedule till you get out of the class; and, should you have to repeat the class (which is common for such classes), you'll not be under as much of a burden due to your gained familiarity with the material.
In short, hang in there; but, hang in there smart.