For me personally, I think it's too soon to forgive them. The past six months have been the first time in my life that I've allowed myself to feel all the pent up rage I have towards them. It's the first time that I've stopped making excuses for their behavior too. I feel like I need to process all this anger before I can forgive them. And even then, I'm not sure I want them back in my life. They've continued to disappoint me even well into adulthood. For example, they chose to go on a long vacation instead of being in town during the birth of my first son (their first grandson). They missed his first birthday party as well, despite living only 45 minutes away.
That's interesting that you advise staying away from shrinks. Did you have a bad experience? I've been relying heavily on my therapist (and books written by therapists) to help me process these realizations. It's been extremely painful but overall I've found it helpful, especially the books.