Rick drives me crazy!! BUT, I felt like Rick had stuffed everything down since he killed Shane, and he zeroed in on one single purpose: finding some kind of safe haven for Lori to have her baby, while keeping everyone else alive. So when Lori did die, and he'd failed (and Carl had to do the worst), everything he'd suppressed finally came pouring out, and he broke down in a giant PTSD event. Andrea and Carol each had a terrible loss, but Rick had all the pressure, and I think his breakdown was mostly based on guilt. He even carried guilt for what happened to Sophia. Each person suffers their losses, but Rick feels those in addition to his own, because he's made himself responsible for the group.
Also, Rick was a few months behind everyone in their coping with the situation, because he was unconscious for the collapse of society, and he had to catch up to the others in terms of really grasping the enormity of what's happened to the world.
As far as his indecisiveness goes, I think it was all about being almost incapacitated by being afraid to make a mistake. But hopefully they're all learning, that whatever decision you make, someone's still going to die. So you have to act and move on. Which is how I interpreted the ending of the first half of the season when he said, "Don't look back."