This is literally a nightmare I once had. I dreamt that I found a time machine and started changing my past little by little, working backwards and fixing minor mistakes, then bigger and bigger ones, but seeing no major impacts on my life. Like fixing a flunked exam only changed the diploma to a “with honors” one and nothing else. But I kept going until a certain event in my life that had really profound impact on my emotional health and made me attempt suicide, but it was also the one that really shaped me into who I am today. After preventing it, bam, Im in a place and a role the current me would’ve never wanted to be in, and the guy I turned into probably didnt want either, it was just so much worse off. After that dream I started to go much more easier on myself. I still cringe from time to time when I remember my past actions, but I dont really regret what happened anymore.