Jeff, I'm truly sorry to hear about your Mom and your Dad. This is a very bad time for you, and nothing I can say will make it better, but I'd like to try to make it maybe a little less bad.
Having both parents pass in such a short period of time is terrible, almost too much to bear. There's almost no way to make sense of it, and that's what we try to do in times of stress or loss, we try to make sense of things. The human mind is accustomed to order and reason, and lacking these, we try to impose them on random or chaotic events. It's why we see shapes in clouds- we try to understand things on our terms. There's not much understanding this, other than what's already been said- your Dad followed your Mom. That happens more often than you'd think, way more often.
Sometimes, like now, the reality is that things can really suck. You just got a major helping of suck, one you didn't ask for, and certainly didn't deserve. I've been there, to some degree, I lost my Dad very suddenly about 11 years back. My Dad was healthy, as far as anyone knew, and then he was gone, in the blink of an eye. I've got his chainsaw, and some shirts that don't fit, and not much else. There was no way to understand it, no way to cope. Your grief is like that- there's not much relief. In times like this, things can get a little mechanical- you get up, you go to work, you come home, you eat, you sleep, repeat. That's not a bad thing; routine is comforting and useful, not to mention that it pays the bills. Routine will help you through some of it.
Friends and family will help with the rest. Talk to them, they're there for you, or they damn well should be. If they're not, AS will help pick up the slack. They're a good bunch here. Tell stories, share memories, talk about your Mom and your Dad. Focus on the good, that's enough for now. Remember the best parts, and acknowledge the sadness. When it hits really bad, let it wash over you, and then let it fade a little. Talk some more. It's OK to be sad, this is a sad time. Be sad in a group if you can. Be happy when you can find the time. Write down some stuff about your parents and post it here- I'll be happy for the opportunity to get to know them (and you) a little better.
Trust me on this: It'll get better. Slowly, very damn slowly, but the pain will ease. Little by little, you'll come to some kind of peace with this, you'll make some sense of it. Not now, not even soon, but eventually, you'll find some peace. It won't get less sad, but it will get less hard. You'll be Ok, even though you're hurting bad right now.
I see a lot of folks who've lost parents, and plenty who've lost spouses, and some who've lost brothers and sisters and children. I attend more funerals than I'd like. Losing a loved one sucks. No two ways about it, it sucks. when that loved one lived a full life surrounded by people they loved, that helps it suck a little less. Lots of small things, (and people, too) will help it suck a little less. Find the small things that help.
I'm really, really sorry about your Mom & Dad.
Bill