The first time my heart got broken, it took me a good couple of years to recover from it. When you've had your heart smashed, kicked and hung out to dry, you just want to forget everything. Especially when you truly and madly loved the person. The heartbreak taught me a lot of things, and I came out a totally different person. Time, acceptance and closure are the ultimate healer. It's true that when one door closes, another opens.
Hopefully, this my take that I wrote a little while ago can help.
It takes time, dedication and effort. You must allow yourself literally to "feel" every emotion. I want you to understand it's okay to feel down. It's okay to cry. Let it all out. The more you release, the better it will be for you. You are allowing yourself to deal with your emotions, instead of bottling them up. When you get too sad, do things that will brighten you up. Hear your favorite music, go out with friends. And remember, time is the biggest healer nothing happens overnight.
There is no certain time. It could take you one month, three months, a year, six years, or a lifetime to truly get over someone. You could possibly even always have feelings for the person. But you must remember why it didn't work out.
Don't dwell on the past. Learn from why the relationship wrong in order to continue forward, and find the one it will work out with. Life is to short to dwell and be sad over one person.