I'm sure you are going to get lots of advice on how to get your son to sleep longer. My youngest son was never much of a sleeper either. We co-slept until he was about 9 months so it wasn't hard to pat his back or give him some milk if he didn't settle down right away. But I'm not suggesting you should do the family bed if you don't want to. I was never able to let him "cry it out" either. And the one time I tried, he ended up throwing up all over everything. So, instead of spending 20 minutes feeding him and getting him back to sleep, I spent an hour cleaning up him, his crib, and getting him settled down again. But that is a personal decision and I don't think either way is better. Just remember no matter what you decide to do, you can't MAKE a baby sleep. Some do, some don't. You can create an environment most conducive to sleeping, but that's about it.
I want to give you a little advice independent of how to get him to sleep. First, your son will reach a point where he will sleep through the night consistently. It may be in a few months, or even a year, but he will do it. How many parents have you heard asking how to get their 3 year old to sleep through the night? But, even if you get your son to sleep through the night again soon, chances are he will have more periods where he can't sleep... be it from a cold, teething, growth pains, whatever. Whatever happens, whether he sleeps or not is not any indicator of how good a parent you are.
So my advice (something I didn't follow with my first son but an so glad I did with the second) is simply do not keep a running tally of how much sleep you have had. It doesn't matter. You will sleep plenty once your son is older. But for right now, it only creates more stress because instead of thinking, "I'm so tired", you're thinking, "I only had 2.5 hours of sleep last night." Either way, you're tired. Do not keep a running comparison of your sleep versus your husband's either. Again... not worth it. You are going to be under a lot of sleep-deprived stress, don't add to it. It only leads to anger and resentment. You can be tired, or you can be tired and angry, either way...you're tired, so choose not to be angry.
Good luck. Hang in there. It will get better.