Like said above...there is not much we can say to you that will ease that pain today.
What can be said?....It will get better with time.
Will it ever go away?....No. Your heart is permanently changed. It will scar over and the pain will become less severe, but it will be a new heart...never the same one again. Sorry, wish I could tell you different but I can't and be truthful with you.
Can you survive it?...YES. Your dad is INSIDE YOU. The very essence of him is strong within you. You will learn to accept that for what it is. With time. No, you don't have him physically by your side here on planet earth anymore. I know that, today, you can't fathom how anything could replace that. Trust me/us. With time, you will learn that having him inside you...although not equal to physically beside you...has its benefits as well. You won't ever have to go find him to ask him what he thinks about this or that...because he is WITH you...all the time.
Now...all that said....TIME. You have to survive. Keep living. Don't quit or give up. Do whatever you have to do to allow the days/weeks/months pass by. Get away from this date...down the road...get TIME between now and then. Then you will see I was right. If you don't, you'll never know.
You can do this. You. You only. With your dad to help you. He's there. Let him help.
I wish you luck, in your search for time.
TC