Hey flamingo, that sounds torturous. I'm guessing that you have lost one parent now? Which is huge. No wonder you have been feeling lousy and no doubt still do to an extent.
Your friends haven't come through for you and that must really hurt. For me it would be a deal breaker. If they can't be there when we are at our lowest ebb, they are not true friends, I say.
However, you say you would like to reconnect so clearly you are more forgiving than me.
Could you text one suggesting meeting for a drink? How did you usually communicate? I'd keep it pretty short and breezy ... hey, it's been ages. Hope all's well with you. Fancy meeting up?
Little steps. Remember not to expect much. If you're still feeling fragile try to have a plan, a time limit, off limits conversation, that sort of thing. Because sometimes the things people don't say can be wounding.
Do your friends still have their parents? I'm guessing they do and simply don't know what to say so have said nothing.
Trouble is, you cannot revert to normal, you will have changed. So part of your plan could be to try to build new friendships with. Better quality people who are not afraid to talk about real shit. Maybe through voluntary work which tends to attract kind-hearted people or some sort of club. Sorry not sure what to suggest...I need to do the same.