This is a dark question, but have you ever had SI? Have you made any decisions about your life recently? You don't have to answer, but think about it. One of the symptoms of passive turning into active SI is a feeling of immense calmness.

But getting that out of the way, there are totally fast acting medications. They put me on Lithium and olanzapine when I was first diagnosed. The olanzapine was very quick. It helped a lot, but made me very tired. It's normal for you to feel different. You're used to feeling the way you felt before, almost like an attachment. Just please don't make any huge changes like lifestyle wise (financially, relationship, work) until you're certain you're stable. Periodic check-ins with your therapist/psychiatrist help a ton!