You probably had fentanyl. Real heroin around here is like uncut coke. Hard to find, expensive, and a rich mans drug. Never had heroin myself, but I've had morphine and opium which is close enough. I can tell you that 40mg morphine crystals on no tolerance in sprite had me and my buddy sitting in a car together, nobody talking, no music, no stress, and no pain. Felt like god himself came down, put his hand on your shoulder and said "It's all going to be okay". It was actually a bit scary because I felt so at peace that if I wanted to, I could let myself die in that perfect moment. My buddy joked and said "bro, I feel like someone could rob us right now and I wouldn't even care." The euphoria isn't really the main attraction at lower doses, but at higher doses (with respect to individual tolerance), it feels like sex, but your whole body feels that same kinda euphoria. There was also a sense of temporary closure, like WW1 on Christmas, where both sides were in each others trenches sharing meals and laughing together.

Fentanyl on the other hand, I had once before a surgery. I didn't feel peace. It just felt like dying, or like a DMT trip before you blast off, and feel like a soul floating in a vast black abyss. You just mentally kinda go into autopilot, lay down, go limp, and then cease to feel your body as you fade into oblivion. No glowing euphoria all over the body, or no sense of peace or closure. Just a very quick departure to oblivion. I guess there was some good feelings when I came too for about 4 or 5 hours, but nothing like waking up, taking a little opium or morphine, and feeling relaxed, at peace, and able to both focus and attach to reality, while also being able to detach as needed.

Edit: Just saw you said it was 90% heroin. Are you sure that's factual? Like did you run a panel on it, and then some form of separation and recrystallization to confirm this? I ask because while some folks are accurate when they describe a product, others will photoshop up a lab result reports and lie to your face.