I definitely get this. It happens at least once a year to me. The first time it did, I immediately called my doctor because I was so terrified. The snap can be so unsettling. To go from being swarmed in sui thoughts to feeling invincible instantly is a wacky shift. But it's also ok!!
Enjoy the relief. Check in with your partner and your doctor to make sure you don't fly into mania. But mostly, phew! The depression has lifted and you can enjoy your life. Rejoice!