Broken sleep function

I think one of the most common questions I get from people who find out I'm a new mom is "does he sleep well?" and, not because they've said anything to insinuate this, I often feel like a bad mom when I say no.
Kiernan is 6.5 months old, and we are lucky to get 4 hours in a row, ever. I am blessed with a husband who helps me in the middle of the night because I don't think I could do it on my own. 4 hours in a row is good, we often have him waking up every 30-60 minutes during the night. It might not take much to get him back to sleep, but he wakes up and we have to go to him. It's exhausting and it's really starting to take its toll. As I write this he's been down for bed for an hour and a half and we've only had to go to him once so far - this is a good night.
I've been getting really discouraged lately, and that itself can make you feel like a bad mom. How can I be so grumpy and fed up all the time when i have this fabulous little guy in my life. And he really is amazingly fabulous! But I'm tired, all the time.
A friend, and mom of a non-sleeper, once said to me that it's having a non-sleeping child that shows you just how effective sleep deprivation is as a method of torture. You spend a night or two of ALMOST falling asleep over and over again before having your baby cry for you... it'll drive you to insanity pretty quickly.
Soon we will start some kind of sleep training, so that, in theory, Kiernan can help himself back to sleep when he wakes up in the night and all he needs is his soother. And we're a step in the right direction with him being able to replace his own soother now. But, it's a very daunting thing to undertake, sleep training. You know it's going to be a lot harder before it gets easier, and god, I have no energy for harder right now.
Here is a post that struck a cord with me, especially the way I've been feeling lately. I love him with all that I have. But you just can't understand what 'hard' really is until you're here.