Is it possible for the heart to heal completely?

i am 33 and havednt had the best start when it comes to relationships. i got divorced when i was 26 and have a sone from the marriage. i met someone else afterwards and we got engaged, bought house, planned baby etc but he left me when i was 6 months pregnant and it was the most almighty shock as i didnt see it coming, i was devastated and couldnt believe it had happened to me but had to keep going and wouldnt have done it without family and friends-i was literally heart broken like i never new was possible. my son is no 21 months and i adore him as i do my other son. however, i am not needy of a relationship at all as my life is pretty hectic with work, kids, and running my own home. but my question is do you ever really get over a broken heart, can i be happy again or is the romantic innocence that once was destroyed and will i remain cynical forever, cos u never forget how someone makes you feel do you??? im ahppy with my life but i just dont think i can ever see myself opening my heart up to anyon ever agin and that makes me feel quite sad but i just dont think i will be able to do it as ive had so much hurt from men. im totally confused by this. id love to hear your experience and views please.