Hello H.,
I dont really have any answers for you but I am in the exact same situation as you are. I have an almost 6 month old son who started waking up more at night, not really crying but just fussing and moving around and also started taking very short naps. The nap thing is driving me crazy! He was taking 45 min naps exactly and this week has started staking 30 min naps. I dont know why or whats going on...its very frustrating. He is so over tired. I have decided to somewhat follow the no cry sleep solution and today started letting him cry. First nap he cried for an hour and I had to go in and pick him up, he had no morning nap :( . 2nd nap he slept for 30 mins and in the book it states to leave them in the crib for another 30-1 hour to see if they fall back asleep, nope didnt work for me. 3rd nap was 30 mins again and I just couldnt let him cry after he woke up, it seemed too much already for the day. Finally at his 4th nap, he cried for 8 mins and fell asleep for an hour and 18 mins! woohoo! Now, I dont know if he was just so exhausted and thats why he slept for so long or if something was finally clicking with him. I guess I will find out tomorrow.
I just wanted to tell you that you were not alone and I feel your pain. Trying to deal with this and potty training my toddler is really hard for me...I can only hope that it gets better.
Please post your progress or message me personally as I would love to know what works or doesnt for you. Most of the other moms I know have dream sleepers who nap for 1 to 2 hours...I feel terrible when I talk to these moms. lol