That’s really hard, especially when it sounds like he was a lot of your life focus. I would be as worried as you, it sounds like you arent able to get any answers at the moment.
To protect yourself, could he have ghosted you in this way to make it easier on himself? Had he ever been conflict avoidant? It’s shitty, but i hear a lot of younger people, without respect to the pain they are causing, flaking out in such a manner.
It may be important that you see if you can find some friends, someone to support you but who you’re not so dependent on. It’s a horrible feeling to have our stability dependent on someone else when sadly humans can be such flawed and weak creatures.
It’s so important you find something inside yourself for you. I have been depressed a long time, (not nearly been put in the situation you have been with a partner) and for me i settled on a weird philosophy that i didn’t choose my birth, but (i am not religious or spiritual) if i go too soon, ill never have a chance to know or experience anything when i die. For me ive settled on leaving when it happens, and trying to get through each day one day at a time.
It’s unlikely that’ll work for you, too, cause it’s such a personal thing to figure out. Im guessing your parents wouldn’t get you a therapist just for you to talk shit out?