Help please--I'm getting stuck in my head :/

I was trying to start writing a short paper due tomorrow for one of my college classes when I suddenly flashed to this really negative thought/memory, and then I just started getting a bunch of negative thoughts about myself. I started getting the feeling like I do before I get stuck in my head and start emotionally spiraling....

It usually doesn't end well :/. I don't self-harm physically, but emotionally I end up submitting to my thoughts and throwing myself off cliffs and into brick walls at full force. I'm afraid that I won't be able to control it again tonight, because fighting it is just too hard sometimes. I've decided to give myself a break and just be okay with not getting my paper done tonight since if I were to push forward I would 100% get stuck for sure... These feelings feed off my force that tries to push them out anyways.

I've been talking about self-compassion in T, but I really don't know what to actually DO at these moments to stop beating myself up, when I'm not 100% in control of the random thoughts sprinting throughout my head.

How do I gain control? I was hoping to get some suggestions so I know how to combat this better in the future. I don't like being scared of losing to my own thoughts :/.

Thanks,
--CHANGEwillcome

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.