Hi M.,
Trust me I KNOW your pain! And what your doing is probably not the issue. I think that for sure it is "personality". The interesting thing is that you say he is 10 months old.. so he'll be a year I guess in May? Or close? My daughter who is 5 yrs old, the youngest of 5 children is the ONLY child that has had difficulty with sleep. She never slept through a single night until she was 3 yrs old. We tried everything! I honestly think it is hereditary. I've always been a light sleeper, I dream all night long and I don't go to sleep easy.. it has to be pitch dark and extremely quiet or I lay there for hours.
Of all the things we have learned from our "non-sleeping" child, the best advice I can give you is the following:
#1 - TEAM WORK - No matter how much your husband works, if you are both trading off getting up during the nights.. you both get a little more sleep. Maybe try your night one night, his the next.
#2 - Consistency - Bed time for our youngest has to be CONSISTENT - She is a gemini.. and one thing about gemini's is that they LOVE routine. If we keep her up later than usual it will FOR sure be a horrible night.
#3 - I would skip naps. Make sure he is tired at night.. keep him awake as much as possible during the day then make sure he is nice and full and worn out (playing) when he hits the sack. When I abrubtly ended naps with our youngest, she actually started waking up less during the night.
#4 - Another thing.. this is debatable but worked for us on many nights. We knew she was not "needing" anything. She had a HARD time getting back to sleep when she awoke during the night and became dependant on us coming in and getting her back to sleep. So we started letting her cry. We'd comfort her and say.. it's ok.. now go night night and leave and let her cry for 10 or 15 minutes.. if she still cried, we'd go back in and say 2 words then leave again for 20 minutes. Eventually, she stopped crying and would fall back asleep. Keep in mind.. while it worked most nights.. it was still very much disturbing our sleep having to get up and comfort her at ALL!
Also, keep in mind that you are also "extra" tired right now .. especially having 2 little ones and being pregnant! That was the only time during my life I could sleep .. during pregnancy! I don't know how I would have made it had I been pregnant when our youngest was 10 months old.
My daughter is now 5 and still wakes having dreams or just crying for no reason in the middle of the night but usually only 2 or 3 times per week. Usually a comforting word or two is all it takes. But we are downstairs and she is upstairs so .. it's still a pain!
Good luck!
W.