How do I get over being so sad???

There is no magic potion. There are tricks that help. But if you could get over it that fast, then was it all you thought it was? Did it really mean that much? As far as I know, the only way is to fill that void with other things and other people, assuming it's really final you are ready to let go move on.

Being sad is part of breaking up and it takes time (months is more likely than days) Generally when I have someone end a relationship, I call a friend and sleep with her. It seems to help.

Be prepared to be sad for a lot longer. Five years together is a really long time, so don't be surprised if you feel this way for a few months. Feelings can't just disappear overnight, but it's a natural to be sad after a break-up. Just keep yourself busy and don't let your mind wonder about the "what-ifs", as it will make you only sadder. Trust me, dude.

You have to take the time to be sad. Don't try to push it aside because at one point in your life you are just going to have to deal with the hurt and pain from the breakup so you might as well deal with it now. But experts say that it takes half the time you were with the person to fully get over them. So in about 2 1/2 years you will be fully over him. But like I said it is going to be sad and it is going to be hard but you have to deal with the pain just for a little bit.