I'm not sure if this might help but this this is what was recommended to me.
My T reminds me that the negative thoughts or criticisms that I have about myself are not facts, only feelings that will come and go with my mood. When I have them, that in addition to practicing self compassion, that to look at them head on and face them with the true facts. So that for example if I have the thought, "I can't do this", combat it with, "what can I do?" and usually something presents itself. If "I am no good", well, that's not true about everything, then list what I am good at. If I am "stupid", well, I may not have known this one thing but there are somethings that I do know and I can learn or with practice I might learn it, etc.

For the negative memories, the past has happened and I cannot change it, and the same with something that might be anxious about in the future... if I focus on something in the present, it is impossible to concerned about the past or stressed out about the future. It can be hard as the mind wants to keep going back to those places. I now picture an older stereo with a dial, with "past", "now", "future" on it. When I get in those moments, I envision physically dialing it back to "now" and then focusing on the task at hand or finding something to distract with. I have to keep doing it but it makes the task a little easier in my mind to switch to.

I don't know if this helps but I know how hard it is to struggle with the negative thoughts and memories. Good luck on your coursework. Hang in there.