I'd add, most people don't have the misfortune of losing their parents young and really lack the ability to comprehend the impact it has. I have no time for people who act as if losing a parent 60 seconds past your 18th birthday is identical to losing a 96 year old parent.
If you find people older than you who still have living parents, or people who lost their parents in their late nineties, trying to tell you how to grieve or pressuring you... You would not be overreacting to tell them to get lost.
These people have no clue what it's like to lose a parent young. If they don't have the ability to empathise and recognise that it is not remotely comparable to losing an elderly parent (or how they hypothetically imagine they'd feel when their parents eventually die), their opinion is irrelevant.
Yes, losing a parent at any age is devastating. But losing them before you have the chance to have an adult relationship with them, or share that stage of your lives together, or have their support as you build your life, or even see them live to build their own life after you've flown the nest, or to retire, is an entirely different thing. Especially as you watch all your peers, and people years older than you, merrily take it for granted that their parents will be part of their lives for decades to come.
It's not just their loss you're grieving, it's your shared future and dreams too - a future that everyone around you is busy living out. Never mind the shock. When an elderly parent dies you know to expect it and gradually prepare, when a young parent dies you don't and can't.
Op, it's ok to feel all the things you're feeling. It is survivable. Finding other people who can relate helps so much, as you'll be able to talk about it without having to explain why you're feeling how you are. The turning point in my grief was the first time I got to talk to somebody else who'd been in similar shoes to me and just "got it". There are often support groups if there is nobody in your own circle you can connect with. I hope my posts haven't been too much, I just wanted you to know you're not alone. Anything you're feeling is okay.