i'm just going to assume you're a good person.
just know that a lot of people have experienced what you have gone through. it's definitely not easy.
the intensity and length of the hurt will depend on what sort of person you are and the cause of the heartbreak. time does heal, but there are steps you can take to potentially help you get past it faster.
some good ideas are to delete pictures, contact information, and similar things of that person.
try and occupy your mind. pick up a new hobby, go volunteering, or go out with friends if that's your thing.
breakups are inevitable, even if you do "all the right things".
you feel the way you feel because you just don't expect someone to treat you like that when all you did was offer your affection and love (i assume).
the feeling of being wronged and blindsided is probably one of the worst feelings imaginable.
but on the brightside, you now know that they're a complete waste of your time.
don't close yourself off from the world because you were wronged by one person. look forward to the thought that you're potentially able to meet someone better that's actually deserving of you.
good luck.