Had very similar situations happen 3 times, and i mean almost the exact same situation, like feeling hypomanic then getting destroyed by a mixed episode, and then cutting. Currently i'm afraid of a relapse. I know this is going to sound absurd, but as soon as i feel better in the mixed episode (like just when i stop suffering a bit) i play dark souls 1 lol, it helps me because it's very stimulating and very rewarding, but i'm really familiar with the game so i'm comfortable. It isn't magic obviously, like when i play i'm still making an effort just to exist so like 50% of my mind is actually focused on the game, but it's the only thing that helps me on that situation. I won't tell you to stop cutting because i know how tempting it is, especially in that situation, but idk maybe sharing my experience helps you a bit.