My DS went through this around 8-9 months as well. I could tell he was so exhausted and overtired but he fought his naps like a wildman! He doesn't sttnnight either.
I started scheduling his naps and it has made a world of difference. I was really stringent about it for a few weeks until he got in the groove and now I can be a little more flexible and follow the schedule loosely based on his cues and how he slept the night before.
I should add that I always rock or nurse him to sleep and during the initial time when we were getting on the schedule I held him for every single nap because that's the only way I could guarantee he would nap well. Now I usually lay down and nap with him in the morning and put him in his crib in the afternoon.
Good luck I know that is so frustrating!